Answer:
Pure iron is a pure substance.
Explanation:
Pure iron is a pure substance because it's chemical composition stays uniform regardless of it's sample size. It's matter that appears uniform in appearance and composition, no matter how small the sample size. An example of a pure substance includes pure iron
2) Which one
more active in between
Li and Na and why ?
IS
Answer:
sodium(Na) is more active between Li and Na because is larger in size. Outermost electrons are less tightly held in sodium than in lithium. As a result, sodium loses its outermost electron more easily than lithium.
What two properties of matter are used to determine density?
An atom has 14 protons, 17 neutrons, and 18 electrons. What is its mass number, atomic number, and charge?
Answer:
Mass number = 31Atomic Number = 14Charge = -4Explanation:
14 protons
17 neutrons
18 electrons
Mass number = ?
Mass number = protons + neutrons.
[tex]Mass\:number = 14+17\\\\Mass \:number = 31[/tex]
Atomic number = ?
The number of protons = atomic number.
Atomic number = 14
Charge = ?
The charge of an element = number of protons minus the number of electrons.
[tex]Charge=14 -18\\\\Charge = -4[/tex]
How do I solve Convert 496 cm to meters
Answer:
4,96 m
Explanation:
100 cm =1m
496 cm =4, 96 m
How many valence electrons does the element with the following electron configuration have? 1s22s22p63s23p64s23d104p4
Explanation:
please refer to the attached file (English)
s'il vous plaît se référer au fichier ci-joint cher compagnon (French)
The number of valance electron is 6
Valence electrons are the electrons found in the outermost shell of an atom.
The given atom has the following electronic configuration;
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
The number of valence electron in a given electronic configuration is determine as follows;
if the last configuration ends in s-orbital, the valence electron is the number of electron attached to the s-orbitalif the configuration ends in p-orbital, the number of valence electron is obtained by adding the electrons in p-orbital and s-orbitalThe number of valance electron is found in this sub-orbitals = 4s², 4p⁴
The number of valance electron = 2 + 4 = 6
Thus, the number of valance electron is 6
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When 1.20 moles of MgO reacts as completely as possible with 0.900 moles of NaCl, the total number of moles of reaction products is:
MgO (s) + 2 NaCl (aq) → MgCl2 (aq) + Na2O (aq)
Answer:
Explanation:
limiting reactant is NaCl it is consumed completely)
calculate n for each product
n NaCl (mole ) n MgCl2(mole )
2 1
0.9 x
x = 0.45 mole
n NaCl n Na2O
2 1
0.900 x
x = 0.45 mole
the total number of moles of reaction products is: 0.45 + 0.45= 0.9mol
Potassium (K) and calcium fluoride (CaF2) can both be classified as
(Please help)
Balancing
equations
• Check that the Synthesis reaction is selected and
that all coefficients are set to one. (The
coefficients are the numbers in the boxes.)
Introduction: The equation H, + O, H,O is unbalanced because there are two oxygen atoms
on the reactants side of the equation, and only one on the products side of the equation. To
balance the equation, you cannot change the structure of any of the molecules, but you can
change the number of molecules that are used.
Question: How are chemical equations balanced?
1. Balance: Tum on Show histograms. The equation is balanced when there are equal
numbers of each type of atom represented on each side of the equation.
In the Gizmo, use the up and down arrows to adjust the numbers of hydrogen, oxygen, and
water molecules until the equation is balanced. When you are done, turn on Show
summary to check your answer.
Write the balanced equation here:
H2+
Н,0
to see other
Synthesis of reaction can be done by adding two or more reactants to form a product.
The chemical equation are balanced according to the law of conservation of mass. It means that the mass of products on the right side should be equal to the mass of reactants on the left.When the number of the product and reactants are equal on both the sides than the equation is said to be balanced.Equation for the water can be balanced as follow:
[tex]2H_{2} + O_{2} = 2H_{2}O[/tex]
The atoms of hydrogen are balanced on both the sides, also the oxygen are balanced.
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if I fertilize my plants they will grow taller is a certain conclusion data-analysis hypothesis or scientific observation
0.15 gm of metallic oxide was dissolved in 100 ml of 0.1 N H2SO4 and 25.8 ml of 0.095N NaOH were used to neutralise the remaining H2SO4.Calculate the equivalent weight of metallic oxide and metal.
Ans: metallic oxide=19.87
metal=11.87
Answer:
Explanation:
25.8 ml of .095 N NaOH is needed to neutralise the remaining acid
equivalent of NaOH used = 25.8 x .095 / 1000 = .002451 gm equivalent .
acid remaining = .002451 gm equivalent .
acid initially taken = 100 ml of .1 N / 1000 = . 01 gm equivalent
acid reacted with metal = .01 -.002451 = .007549 gm equivalent
This must have reacted with same gram equivalent of metal oxide
.007549 gm equivalent = .15 gm of metal oxide
1 gm equivalent = 19.87 gm
equivalent weight of metal = 19.87 - equivalent weight of oxygen
= 19.87 - 8 = 11.87 .
1
DONE
One of the following properties was originally used to arrange elements on the periodic table, but is no
longer used to organize the modern version. Which property fits this description?
atomic number
atomic mass
chemical properties
DONE
Intro
FR
Answer:
The correct answer is atomic mass
Explanation:
on engenuity
Answer:
The correct answer is atomic mass.
Explanation:
I took the quiz on edginuity
If 175 undecayed nuclei remained from a sample of 2800 nuclei, how many half-lives has passed? *
Answer:
209
Explanation:
Answer:
Four half lives
Explanation:
Two samples of matter differ in temperature by 20°C. Describe
the difference in temperature of these two samples using the
Kelvin scale.
Given :
Two samples of matter differ in temperature by 20°C.
To Find :
The difference in temperature of these two samples using the Kelvin scale.
Solution :
Let , initial and final temperature is [tex]T_i[/tex] and [tex]T_f[/tex] .
So , [tex]T_f-T_i=20^oC[/tex] .
Now , temperature in kelvin is given by [tex](T_i+273)[/tex] and [tex](T_f+273)[/tex] .
So , difference between them is :
[tex]=(T_f+273)-(T_i+273)\\\\=T_f-T_i\\\\=20\ K[/tex]
The difference in temperature of these two samples using the Kelvin scale is 20 K .
Therefore , the magnitude of difference in kelvin and Celsius is same .
Hence , this is the required solution .
Which statment correctly decribes a law?
can be changed or replaced
is a factual statment
is not based on observations
A chemical property of oxygen is that it ____
a.) is the most abundant element in earth's crust
b.) combines with hydrogen to form water
c.) boils at -183 Celcius
d.) has a density of 1.43 g/l
WILL GIVE BRAINLEST + THANKS! <3
Answer:
the answer you are searching for is
how many kilojoules is 1,500,000 calories
Answer:
1 cal = 0.004187 kJ
1,500,000 cal = 6280.5 kJ
Which statement describes the formation of metamorphic rocks?
Rocks beneath the surface melt.
Rocks above the surface are eroded.
Rocks beneath the surface are forced toward the mantle.
Rock layers near the surface decrease pressure on layers beneath them.
Answer:
rocks beneath the surface melt seems like the answer that makes the most sense
Answer:
Rocks beneath the surface melt
Explanation:
What did researchers at Virginia Tech try using to help reforest post-mining site soil?
Answer:
Researchers at Virginia Tech decided to try using biochar to help reforest the post-mining site soil. They got permission to apply a layer of biochar to a post-mining site before it was reseeded and replanted.
Which ions produce similar colors in the flame tests?
Answer:
Two ions that produced similar colors in the flame test were Ca+2 and Sr+2. 3.
Explanation:
The colors are produced when an electron jumps to a higher level and then jump back down.
Ba2+ and Cu2+ and Sr2+ and Li+ were the pair with the similar color. Sr and Li displayed red colors, while Ba and Cu had mild greenish yellowish hues.
Why do some ions in the flame test generate colors that are similar?
The precise sizes of the potential energy jumps differ from metal to metal. As a result, the flame color of each metal will differ due to its unique spectral line pattern. The movement of the electrons in the metal ions contained in the compounds results in the hues of the flame.
The energy released by each electron when it returns to its initial condition determines the hue of the light that is produced.
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What is the temperature of 0.500 moles of helium that occupies a volume of 15.0 L at a pressure of 1.6 atm?
Answer:
600K
Explanation:
PV=nRT
T=PV/nR
= 1.6atm* 15.0L/ 0.5mol*0.0821LatmK^-1mol^-1
=600K
formula that represents a substance that is a mixture
]Answer:
[tex] H_2O + Mg [/tex]
Explanation:
A mixture is made up of two or more substances or constituents, which combine physically and can be easily separated. In a mixture, each constituent still maintains its identity and property in the combination.
Among the options given, the formula [tex] H_2O + Mg [/tex] represents a mixture of Water and Magnesium. This is a typical example of a substance that consists of 2 different substances that are combined physically.
A company employs several high school students in its food-packaging factory. All the students are below 17 years of age. Which act prohibits
the employment of such persons?
OA. Occupational Safety and Health Act
OB. Fair Labor Standards Act
OC. Perishable Agricultural Commodities Act
OD. Homeland Security Presidential Directives
Answer:
Fair Labor Standards Act
Explanation:
It is correct. I just took the test on Clever
Answer:
I would say it’s B
Explanation:
.Which term best describes the important pieces of information that scientists gather and record during an experiment?
conclusions
data
research
supplies
Answer: Data
Explanation:
The answer is data because data is important pieces of evidence that is collected in a table or a graph.
Answer:
B. Data
Explanation:
Cuz is said so duh
Density = 2 g/ml
Volume = 20 ml
What is the mass?
Answer:
The answer is 40 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 20 mL
density = 2 g/mL
The mass is
mass = 20 × 2
We have the final answer as
40 gHope this helps you
2. Sulfur dioxide (SO2) gets blasted out of volcanoes and reacts with oxygen (O2) in our
atmosphere to produce sulfur trioxide (SO3). If 128 grams of sulfur dioxide reacts with
oxygen in the atmosphere and 160 grams of sulfur trioxide (SO3) is produced, how many
grams of oxygen originally reacted?
SO2 + O2= SO3
4. NH4Cl
What is the compound?
Answer:
ammonium chloride
Explanation:
Because NH is ammonium and Cl is chlorine
Which statement best explains why water has a higher boiling point than ethane?
Ethane molecules are smaller than water and can move faster.
Water molecules need relatively less heat energy to move.
Water molecules form hydrogen bonds, which cannot be broken by heating water.
Ethane molecules have no hydrogen bonds and need less energy to separate.
Answer:
Ethane molecules have no hydrogen bonds and need less energy to separate.
Explanation:
Ethane: has no hydrogen bonding, it has low melting, boiling points, and is a gas at room temperature.
Water: has strong hydrogen bonding between H and O, has relatively high melting and boiling points.
Statement that explains the relationship between boiling point of water and ethane and how the boiling point of water is higher than ethane is D:Ethane molecules have no hydrogen bonds and need less energy to separate.
The boiling point of water is usually high compare to that of ethane because of the hydrogen bonds present in water which is a electromagnetic attraction between hydrogen atom electronegative atom of Oxygen.And which this requires so much energy to break unlike ethane that doesn't contain any hydrogen bond.
Therefore, option D is correct.
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the amount of water vapour in the air is caleed
Answer:
Absolute humidity
Explanation:
How many moles are in a sample of 32.6732 g of lead ?
Answer:
0.157689 moles
Explanation:
0.5 gm of mixture of NH4Cl and NaCl was boiled with 25 ml of 0.95 N NaOH in a vessel till all the ammonia is expelled.The residual solution is cooled and then made up to 100 ml.It was found that 10 ml of the diluted residual solution neutralised by 16 ml of 0.1 N (F=1.06)H2SO4. Calculate the % of pure NH4Cl in the mixture.
Ans:72.66%
Answer:
72.66%
Explanation:
NH₄Cl reacts in presence of NaOH producing ammonia, NH₃, as follows:
NH₄Cl + NaOH → NaCl + NH₃ + H₂O
The residual NaOH reacts with H₂SO₄ as follows:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O.
The equivalent-gram of H₂SO₄ are:
16mL * 0.1N * 1.06 = 1.696mEq.
As the complete residual solution is 100mL but the neutralization was made only with 10mL, the mEq you need to neutralize the residual NaOH is:
1.696mEq * (100mL / 10mL) = 16.96mEq.
The mEq of NaOH you add in the first are:
25mL * 0.95mEq = 23.75mEq
That means the NaOH that reacts = moles of NH₄Cl is:
23.75mEq - 16.96mEq = 6.79mEq = 6.79mmoles NH₄Cl =
6.79x10⁻³ moles NH₄Cl
In grams (Using molar mass NH₄Cl = 53.5g/mol):
6.79x10⁻³ moles NH₄Cl * (53.5g / mol) =
0.3633g of NH₄Cl are in the original mixture.
% is:
0.3633g/ 0.5g * 100 = 72.66%
The percentage of pure NH₄Cl in the mixture = 72.66%
Given data :
0.5 gm of mixture of NH₄Cl and NaCI
25 ml of 0.95 N NaOH
Determine the % of pure NH₄Cl in the mixture
Given that the reaction equation of the mixture is ;
NH₄Cl + NaOH ----> NaCl + NH₃ + H₂O
And the residual solution reaction with H₂SO₄ is
2NaOH + H₂SO₄ ----> Na₂SO₄ + 2H₂O.
∴ H₂SO₄ ( equivalent gram ) = 16mL * 0.1N * 1.06 = 1.696
but the equivalent gram of H₂SO₄ required to neutralize NaOH = 1.696 * ( 100 mL / 10 mL ) = 16.96
NaOH⁻ = 25mL * 0.95 = 23.75mEq ( from the first reaction equation )
next step : Determine the number of moles of NH₄Cl
moles of NH₄Cl = 23.75- 16.96 = 6.79 * 10⁻³
Final step : Calculate the % of pure NH₄CI in the mixture
moles of NH₄Cl = 6.79 * 10⁻³
molar mass of NH₄Cl = 53.5g/mol
∴ mass of NH₄Cl = 6.79 * 10⁻³ * 53.5 = 0.3633g
% of pure NH₄CI in the mixture = ( 0.3633 / 0.5 ) * 100 = 72.66%
Hence we can conclude that The percentage of pure NH₄Cl in the mixture is 72.66%
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