Answer:
C. element. oxygen is an element
Explanation:
oxygen is element #8
WILL MARK BRAINLIEST IF CORRECT
Calculate the average rate of change for the graphed sequence from n = 1 to n = 3. graphed sequence showing point 1, 2, point 2, 4, point 3, 8, point 4, 16, point 5, 32, and point 6, 64
A. 1
B. 2
C. 3
D. 6
Answer:it b
Explanation:
I've done that before
Answer:
The Answer is C or 3
Explanation:
I took the test
What’s the answer to this question?
Answer:
“The answer to this question” is more general. The preposition to denotes assignment - that the answer is being “applied” to the question, whether the answer is right or wrong. Conceptually, that makes a lot more sense than the previous one. This is also the more common usage.
A bobsled has a momentum of 4000 0 kg* m/s to the south. Friction on the track reduces its momentum to 500 kg* m/s to the south. What impulse is applied to the bobsled by the friction?
A. 6500 kg* m/s north
OB. 1500 kg* m/s south O
C. 6500 kg* m/s south
O 1500 kg* m/s north
Answer: 1500 kg•m/s north
Explanation:
A PE X
A chemist prepares a solution of iron(III) bromide (FeBr3) by measuring out 41.1 mg of FeBr3 into a 50. mL volumetric flask and filling to the mark with
distilled water.
Calculate the molarity of Br- anions in the chemist's solution
Be sure your answer is rounded to 2 significant digits.
Answer: The molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]FeBr_3[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.0411g}{295.6g/mol}=0.00014mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.00014\times 1000}{50}=0.0028[/tex]
As 1 mole of [tex]FeBr_3[/tex] gives = 3 moles of [tex]Br^-[/tex]
0.0028 moles of [tex]FeBr_3[/tex] gives = [tex]\frac{3}{1}\times 0.0028=0.0084 moles[/tex] of [tex]Br^-[/tex]
Thus the molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M
If two electrically charged objects repel one another, which statement must be true? One object has more electrons, and the other has more protons. Electrons will flow from one object to the other when they touch each other. The two objects have the same electric charge. The objects do not have strong electrical fields.
Answer:
The two objects have the same electric charge.
Explanation:
Electrically charged objects repel if they are both of the same charge, ie plus plus or minus minus.
The statement, that describes two electrically charged objects repel one another is "the two objects have the same electric charge."
What is an electric charge?The feature of subatomic particles that causes them to experience a force when put in an electric and magnetic field is known as electric charge.
When one or more items are electrically charged, electrostatic interactions are widespread. Two items with opposing charges will attract each other.
Unlike the attractive force between two items with opposite charges, two objects with like charges repel each other. In other words, a positively charged object will repel another positively charged object. This repelling force will separate the two items.
Hence the correct answer is the two objects have the same electric charge.
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How does the size of the atoms relate to how reactive it is?
Answer: nucleus
Explanation: the bigger the nucleus there more reactive the atom is
Answer:
The larger an atom is, the more reactive it will be.
It helps to think about the size of an atom with the location of the electrons and nucleus in mind. You know that protons are positively charged and electrons are negatively charged, therefore there is a level of attraction between these two oppositely charged subatomic particles. This attraction helps stabilize the atom.
Now, in a larger atom, with more electrons are those electrons (specifically the valence electrons) going to be closer or further from the nucleus than in a smaller atom?
They will of course be further from the nucleus and therefore further from the positively charged nucleus. This makes it easier for the valence electrons to leave the atom and form an ionic bond or to interact with another atom to form a covalent bond.
If electrons can leave more easily, then the atom is more likely to react.
Classify the following as an element, compound, homogeneous mixture, or heterogeneous
mixture:
Hydrogen (H2)
A. Element
B. Compound
C. Homogenous mixture
D. Heterogenous mixture
Which ion below is present in greatest concentration in a basic (alkaline) solution
Answer:
hydroxide ion / OH-
Explanation:
Basic solutions have a greater concentration of hydroxide ions than hydrogen (H+) ions
Find the Empirical formula for 0.765g Cr, 0.235g O
Answer:
CrO
Explanation:
0.765g Cr
0.235g O
O = 16g/mol
Cr = 52g/mol
O 2-
Cr 2+, 3+, 6+
0.765 + 0.235 = 1
so 76.5% Cr
23.5% O
76.5/52 = 1.47/1.47 = 1
23.5/16 = 1.47/1.47 = 1
CrO
What are these labels?
Answer:
From left to right
Neutral
Acid
Base
Explanation:
So using HSAB theory hard and soft (Lewis) acids and bases.
OH - Is a Hard Base
H+ Strong Acid
A company wants to put a fleet of low Earth satellites in orbit to create a worldwide telephone link. There is less of a time lag in the conversations the closer to the ground the satellites are. What advantage is there to putting them 700 km up, instead of 250 km up in the sky
Iodine-131 has a half-life of 8 days. How long would it take for the number of unstable nuclei in the sample to be reduced from 1,000 to 125?
Answer:
After one-half life: 16 mg
After 2-half lives: 8 mg
After 3-half lives: 4 mg
After 4-half lives: 2 mg
After 5-half lives: 1 mg
(5 half-lives) x (8 days/half-life) = 40 days
or doing it the mathematical way: Let z be the number of days to be found:
1 mg = 32 mg x (1/2)^(z / 8 days)
1/32 = (1/2)^(z / 8 days)
log (1/32) = (z / 8 days) x log (1/2)
z / 8 days = log (1/32) / log (1/2)
z = 8 days x log (1/32) / log (1/2) = 40 days
Explanation:
Iodine-131 has a half-life of 8 days, then it would it take for the number of unstable nuclei in the sample to be reduced from 1,000 to 125 is 512 days.
How do we calculate total time?Total time of the reduction of any substance from an initial concentration to a particular concentration will be calculated as:
T = (t)ⁿ, where
n = number of half lives
t = half life time = 8 days
1st half life: 1000 → 500
2nd half life: 500 → 250
3rd half life: 250 → 125
So number of half life times is 3. On putting values we get,
T = (8)³
T = 512 days
Hence total duration of time is 512 days.
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In a undisturbed layer, how do we know which layer was deposited first ?
Answer:
It's the bottom layer.
Explanation:
Scientists use the Law of Superposition to determine the relative age of a layer of sedimentary rock:
The oldest rock layer is at the bottom of an undisturbed bed.
Thus, Layer A in the figure below was deposited first.
Where does a wolf get energy from?
Where does a rabbit get energy from?
Where does a plant get energy from?
Where does a mushroom get energy from?
Answer:
Check Explanation
Explanation:
In this case the Mushroom would get energy from decomposing dead plants and animals in the soil/ground
The plant would get energy from the sun (simplified)
the rabbit would get energy from eating the plant
in this case the wolf would energy from eating the rabbit but in a normal setting the wolf could get energy from eating any animal
Answer:
Explanation: A wolf gets its energy from food and water
A rabbit gets its energy from food and water too
A plant get it energy from sunlight, rain
A mushroom also get its energy from dead plant/animal’s
If this wasn’t the answer you wanted I’m sorry
Label each element in the chemical reaction below with the correct oxidation state
NH3 (aq) + 3 HOCl (ax)
NCI () + 3 H20 (1)
Answer:
N = -3
H = +1
O = -2
Cl = +1
Explanation:
The balanced Equation of the reaction above is:
NH3 + 3HOCl ----> NCl3 + 3H2O
Where NH3 is ammonia;
HOCl is Oxochlorate (I) acid
NCl3 is nitrogen trichloride
H2O is water
Nitrogen in both Ammonia and Nitrogen trichloride has an oxidation state of -3. It shares three electrons with each of the three atoms of hydrogen and chlorine
Hydrogen in both Oxochlorate (I) acid and in water has an oxidation state of +1. Each atom shares an election with oxyen in both compounds.
Oxygen in both Oxochlorate (I) acid and water has an oxidation state of -2. Each atom shares two electrons with neighboring atoms; in HOCl, it shares with chlorine and hydrogen, while in H2O, it shares with two atoms of hydrogen.
Chlorine in both Oxochlorate (i) acid and Nitrogen trichloride has an oxidation state of +1. It shares an electron with each of it's neighboring bonded atoms.
PLS HELP!! Need help with this asap.
Answer:
22.6881 Grams of CO
Explanation:
Fe2O3 + 3CO = 3CO2 + 2Fe
Ratio
1:3 = 3:2
How many grams of CO are needed to produce 30.2 grams of Fe
Fe2O3 Molar mass: 159.69 g/mol
CO Molar mass: 28.01 g/mol
Fe Atomic mass: 55.845
Ok so our end result is 30.2 Grams of Fe, we have 2 Fe so we have 15.1 Grams per Fe
15.1/55.845 = 0.27
So then we multiply this by 3 as we we know the ratio and get get 0.81 required as this is 3CO.
So we need 0.81 Moles of CO so we need 22.6881 Grams of CO.
What are substances on the right side of a chemical equation
called?
a. reactants
b. groups
C. products
d. electrons
Answer:
The substances on the right side of a chemical equation are the products as reactions typically move from left to right.
A chemical equation is a representation of chemical reaction in the form of symbols and formulae where the reactants are on left side and the products on right side.
Eg. CaCO3(s)→CaO(s)+CO2(g
What is chemical equation?Chemical equation is written "with the reactants on the left side of an arrow and the products of the chemical reaction on the right".
What is a reactant?Reactants are "the starting materials in a chemical reaction".
What is a product?
A product is "a chemical species resulting from a chemical reaction".
Hence, the substances on the right side of a chemical equation are products.
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The following half-reaction can be balanced in acidic solution:
N2O5 --> NH4+
How many electrons appear in the balanced equation?
A. 13e-
B. 14e-
C. 16e-
D. 18e-
Answer:
None of them, answer seems to be 24 unless I messed up
Explanation:
How many electrons appear in the balanced equation
What the heck do they mean, do they mean transferred?
N2O5 --> NH4+
Left Side
N 5+ Electrons 2 in central shell, 5 in outer
O 2- Electrons 2 in central shell, 6 in outer
Right Side
H 1+ Electrons 1 in central shell
N 3- Electrons 2 in central shell, 5 in outer
Hmm, ok so need to balance the half equation first, this is a redox reaction.
Hmm, so it's going to be something like
H2 + N2O5 → NH + O3
Step 1. Write down the unbalanced equation ('skeleton equation') of the chemical reaction. All reactants and products must be known. For a better result write the reaction in ionic form.
H2 + N2O5 → NH + O3
Step 2. Separate the process into half reactions. A redox reaction is nothing but both oxidation and reduction reactions taking place simultaneously.
a) Assign oxidation numbers for each atom in the equation. Oxidation number (also called oxidation state) is a measure of the degree of oxidation of an atom in a substance (see: Rules for assigning oxidation numbers).
H02 + N+52O-25 → N-1H+1 + O03
b) Identify and write out all redox couples in reaction. Identify which reactants are being oxidized (the oxidation number increases when it reacts) and which are being reduced (the oxidation number goes down). Write down the transfer of electrons. Carefully, insert coefficients, if necessary, to make the numbers of oxidized and reduced atoms equal on the two sides of each redox couples.
When one member of the redox couple is oxygen with an oxidation state of -2 or hydrogen with an oxidation state of +1, it is best to replace it with a water molecule.
O:3H+12O-2 → O03 + 6e-(O)
H02 → H+12O-2 + 2e-(H)
R:N+52O-25 + 12e- → 2N-1H+1(N)
c) Combine these redox couples into two half-reactions: one for the oxidation, and one for the reduction (see: Divide the redox reaction into two half-reactions).
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e-
R:N+52O-25 + 12e- → 2N-1H+1
Step 3. Balance the atoms in each half reaction. A chemical equation must have the same number of atoms of each element on both sides of the equation. Add appropriate coefficients (stoichiometric coefficients) in front of the chemical formulas to balance the number of atoms. Never change any formulas.
a) Balance all other atoms except hydrogen and oxygen. We can use any of the species that appear in the skeleton equations for this purpose. Keep in mind that reactants should be added only to the left side of the equation and products to the right.
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e-
R:N+52O-25 + 12e- → 2N-1H+1
b) Balance the charge. For reactions in an acidic solution, balance the charge so that both sides have the same total charge by adding a H+ ion to the side deficient in positive charge.
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e- + 8H+
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1
c) Balance the oxygen atoms. Check if there are the same numbers of oxygen atoms on the left and right side, if they aren't equilibrate these atoms by adding water molecules.
O:3H+12O-2 + H02 + H2O → O03 + H+12O-2 + 8e- + 8H+
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1 + 5H2O
Balanced half-reactions are well tabulated in handbooks and on the web in a 'Tables of standard electrode potentials'. These tables, by convention, contain the half-cell potentials for reduction. To make the oxidation reaction, simply reverse the reduction reaction and change the sign on the E1/2 value.
Step 4. Make electron gain equivalent to electron lost. The electrons lost in the oxidation half-reaction must be equal the electrons gained in the reduction half-reaction. To make the two equal, multiply the coefficients of all species by integers producing the lowest common multiple between the half-reactions.
O:3H+12O-2 + H02 + H2O → O03 + H+12O-2 + 8e- + 8H+| *3
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1 + 5H2O| *2
O:9H+12O-2 + 3H02 + 3H2O → 3O03 + 3H+12O-2 + 24e- + 24H+
R:2N+52O-25 + 24e- + 24H+ → 4N-1H+1 + 10H2O
Step 5. Add the half-reactions together. The two half-reactions can be combined just like two algebraic equations, with the arrow serving as the equals sign. Recombine the two half-reactions by adding all the reactants together on one side and all of the products together on the other side.
9H+12O-2 + 2N+52O-25 + 3H02 + 24e- + 3H2O + 24H+ → 3O03 + 4N-1H+1 + 13H2O + 24e- + 24H+
Step 6. Simplify the equation. The same species on opposite sides of the arrow can be canceled. Write the equation so that the coefficients are the smallest set of integers possible.
2N+52O-25 + 3H02 → 3O03 + 4N-1H+1 + H2O
Explain the difference between layers and band.
Answer:
Foliation is developed by stress and fire while layering is developed by the embedding of fine and coarse deposits. Foliation is caused due to an alteration of minerals from pressure and heat while layering is developed by seasonal changes
Explanation:
Banding occurs when two different mineral compositions alternate in thin layers (typically 1 mm to 1 cm). The two types of layers typically contain the same minerals, but in different proportions, giving the rock a striped appearance. A foliation is defined by its banding.
What is foliation rocks?There are two major types of metamorphic rock textures: foliated and nonfoliated. Foliation in rock is caused by the parallel alignment of Platy minerals (such as Muscovite, Biotite, and Chlorite), Needle-like minerals (such as Hornblende), or Tabular minerals (e.g., feldspars). Because of the parallel alignment, the granite easily splits into thin sheets or layers. Foliation can be found in both aphanitic and phaneritic metamorphic rocks. A few foliated rocks also have bands.A banded rock has alternating thin layers of two different mineral compositions, with thicknesses ranging from 1 mm to 1 cm. The same minerals are found in both types of strata, but in varying amounts, giving the rock a striped appearance. A foliation is defined by its banding.To learn more about foliation, refer to:
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which of the following is a basic salt solution?
A. NH3 (aq)
B. NH4I (aq)
C. KNO3 (aq)
D. Na2CO3 (aq)
Answer:
D. Na2CO3
Explanation:
I'm just guessing tbh
What is the charge on an electron?
O-1
O 0
O +1
O +2
Answer:
-1
Explanation:
Because it is the smallest sub-atomic particle
PLZ SEE ATTACHED AND I WOULD REALLY APPRECIATE IT! ANYONE GOOD WITH CHEM
Answer : The value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The main chemical reaction is:
[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g)[/tex] [tex]\Delta H_{rxn}=?[/tex]
The intermediate balanced chemical reaction are:
(1) [tex]C(s)+2H_2(g)\rightarrow CH_4(g)[/tex] [tex]\Delta H_1=-74.6kJ[/tex]
(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex] [tex]\Delta H_2=-95.7kJ[/tex]
(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g)[/tex] [tex]\Delta H_2=-184.6kJ[/tex]
Now we are reversing reaction 1, multiplying reaction 3 by 2 and then adding all the equations, we get :
(1) [tex]CH_4(g)\rightarrow C(s)+2H_2(g)[/tex] [tex]\Delta H_1=74.6kJ[/tex]
(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex] [tex]\Delta H_2=-95.7kJ[/tex]
(3) [tex]2H_2(g)+2Cl_2(g)\rightarrow 4HCl(g)[/tex] [tex]\Delta H_2=2\times (-184.6kJ)=-369.2kJ[/tex]
The expression for enthalpy change for the reaction will be,
[tex]\Delta H_{rxn}=\Delta H_1+\Delta H_2+\Delta H_3[/tex]
[tex]\Delta H_{rxn}=(74.6kJ)+(-95.7kJ)+(-369.2kJ)[/tex]
[tex]\Delta H_{rxn}=-390.3kJ[/tex]
Therefore, the value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ
What's the sequence of a single complete engine cycle?
Intake, compression, power, exhaust
Intake, power, compression, exhaust
Compression, power, intake, exhaust
Intake, exhaust, compression, power
Answer:
Intake, compression, power, and exhaust
Explanation:
A four-stroke cycle engine is an internal combustion engine that utilizes four distinct piston strokes (intake, compression, power, and exhaust) to complete one operating cycle. The piston make two complete passes in the cylinder to complete one operating cycle.
The sequence of a single complete engine cycle is Intake, compression, power, exhaust. Therefore option 1 is correct.
1. Intake: In this step, the intake valve opens, allowing a mixture of air and fuel to enter the combustion chamber.
2. Compression: After the intake stroke, the intake valve closes, and the piston moves back up, compressing the air-fuel mixture. This compression increases the pressure and temperature inside the cylinder, preparing it for combustion.
3. Power: Once the air-fuel mixture is compressed, the spark plug ignites it. The burning mixture rapidly expands, generating a high-pressure force that pushes the piston down.
4. Exhaust: After the power stroke, the exhaust valve opens, and the piston moves back up, pushing the burned gases out of the cylinder and into the exhaust system.
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Which statement is an inference?
A) A thermometer shows that the air temperature is 56 degrees Fahrenheit.
B) A mineral sample of galena produced a gray-black streak when tested.
C) Based in previous data, ten hurricanes may occur in the year 2013.
D) A weather vane shows the wind is coming from the west.
Answer: C. Based in previous data, ten hurricanes may occur in the year 2013.
Explanation:
Inference can be explained as conclusion made from an existing evidence or facts. Option C, best fits an inference statement.
Answer:
C
Explanation:
because everything looks like opinions
TRUE OR FALSE
As the human population increases, demand for natural resources will also increase.
A sample of octane undergoes combustion according to the equation 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ. What mass of O2 (in grams) must react in order to generate 7280 kJ of energy?
Answer:
[tex]\large \boxed{\text{528.7 g} }[/tex]
Explanation:
It often helps to write the heat as if it were a reactant or a product in the thermochemical equation.
Then you can consider it to be 11018 "moles" of "kJ"
We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.
M_r: 32.00
2C₈H₁₈ + 25O₂ ⟶ 16CO₂ + 8H₂O + 11 018 kJ
n/mol: 7280
1. Moles of O₂
The molar ratio is 25 mol O₂:11 018 kJ
[tex]\text{Moles of O}_{2} = \text{7280 kJ} \times \dfrac{\text{25 mol O}_{2}}{\text{11 018 kJ}} = \text{16.52 mol O}_{2}[/tex]
2. Mass of O₂
[tex]\text{Mass of C$_{8}$H}_{18} = \text{16.52 mol O}_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \textbf{528.6 g O}_{2}\\\text{The reaction requires $\large \boxed{\textbf{528.67 g O}_{2}}$}[/tex]
Which statement best describes the process that the diagrams show?
A solid loses kinetic energy to become a liquid and then becomes a gas
A solid gains kinetic energy to become a liquid and then becomes a gas,
Agas loses kinetic energy to become a liquid and then becomes a solid
Agas gains kinetic energy to become a liquid and then becomes a solid
Answer:Agas loses kinetic energy to become a liquid and then becomes a solid
i believe i had this before but where is the graph
Explanation:
please mark this answer as brainlest
B. A solid gains kinetic energy to become a liquid and then becomes a gas
) carbon + oxygen = _____________
E) calcium carbonate = ______________ + _________________
F) carbon + hydrogen = ____________
G) carbon + hydrogen + oxygen = ______________
H) water = ___________ + ___________
I) Iron + sulphur = _______________
J) magnesium + oxygen = ________________
M) magnesium oxide + water = ___________________
O) carbon monoxide + oxygen = ______________
Answer:
d)carbon(iv)oxide/carbon(ii)oxide
e)Calcium,carbon,oxygen
f)carnonhydride
g)Carbonhydrate
h)hydrogen+oxygen
I)Iron sulphide
j)Magnesiumoxide
m)magnesium hydroxide+hydrogen gas
d)carbon dioxide
Which of the following is true for the theoretical yield of a reaction? (1 point) a It is always calculated as a ratio. b It is the yield from the excess reactant. c It is the yield from the limiting reactant. d It is always twice the value of the actual yield.
Answer:
It is calcualted based ion the yield from the limiting reactant
Explanation:
The picture represents _________________.
A . Compounds
B . Mixture of Elements and Compounds
C. Mixture of Elements
D. Elements
E. Mixture of Compounds
