Answer:
The fourth atom.
Explanation:
Number of valence electrons in each of the four atoms:
First atom: two ([tex]2\, s^{2}[/tex].)Second atom: two ([tex]3\, s^{2}[/tex].)Third atom: eight ([tex]3\, s^{2}\; 3\, p^{6}[/tex].)Fourth atom: two ([tex]4\, s^{2}[/tex].)Without referring to a periodic table, the first, second, and fourth atoms would all belong to the alkali-earth metal elements. The third atom would belong to a noble gas element. (The four choices are beryllium, magnesium, argon, and calcium, respectively.)
Noble gas elements are highly stable. Thus, the third atom (argon) would be the least reactive among all four choices.
On the other hand, alkali-earth metals are reactive since they tend to lose their valence electrons. The reactivity of an alkali-earth atom depends on its ionization energy (the energy required to take a valence electron away from the atom.)
Since these atoms are in the same group, ionization energy would be smaller for atoms with a larger radius. In a given group, atoms with more filled electron shells would have a larger radius.
The first atom has two filled main shells, the second has three, whereas the fourth has four.
Thus, among the three alkali-earth metals in the choices:
[tex]\begin{aligned}&\text{Number of filled electron shells:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Atomic radius:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Ionization energy:} \\ & a > b > d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Reactivity:} \\ & a < b < d\end{aligned}[/tex].
The third choice (a noble gas) is the least reactive among the four choices:
[tex]\begin{aligned}&\text{Reactivity:} \\ & c < a < b < d\end{aligned}[/tex].
Overall, the fourth choice would be the most reactive among the four choices.
A 4.0 L flask containing N2 at 15 atm is connected to a 4.0 L flask containing H2 at 7.0 atm and the gases are allowed to mix. What is the mole fraction of N2
The mole fraction of N₂ after the mixture of 4.0 L of N₂ at 15 atm with 4.0 L of H₂ at 7.0 atm is 0.68.
We can calculate the mole fraction of N₂ with the following equation:
[tex] X_{N_{2}} = \frac{n_{N_{2}}}{n_{t}} = \frac{n_{N_{2}}}{n_{N_{2}} + n_{H_{2}}} [/tex] (1)
The number of moles of N₂ and H₂ can be found with the ideal gas law:
[tex] PV = nRT [/tex]
Where:
P: is the pressure
R: is the gas constant
T: is the temperature
V: is the volume
For nitrogen gas we have:
[tex] n_{N_{2}} = \frac{P_{N_{2}}V_{N_{2}}}{RT} [/tex] (2)
And for hydrogen:
[tex] n_{H_{2}} = \frac{P_{H_{2}}V_{H_{2}}}{RT} [/tex] (3)
After entering equations (2) and (3) into (1), we get:
[tex] X_{N_{2}} = \frac{\frac{P_{N_{2}}V_{N_{2}}}{RT}}{\frac{P_{N_{2}}V_{N_{2}}}{RT} + \frac{P_{H_{2}}V_{H_{2}}}{RT}} [/tex]
Since RT are constants, we have:
[tex] X_{N_{2}} = \frac{P_{N_{2}}V_{N_{2}}}{P_{N_{2}}V_{N_{2}} + P_{H_{2}}V_{H_{2}}} [/tex]
We know that:
[tex] P_{N_{2}} = 15 atm[/tex]
[tex] V_{N_{2}} = 4.0 L[/tex]
[tex] P_{H_{2}} = 7.0 atm[/tex]
[tex] V_{H_{2}} = 4.0 L[/tex]
so:
[tex] X_{N_{2}} = \frac{15 atm*4.0 L}{15 atm*4.0 L + 7.0 amt*4.0 L} = 0.68 [/tex]
Therefore, the mole fraction of N₂ is 0.68.
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A chemist heats the block of copper as shown in the interactive, then places the metal sample in a cup of oil at 25.00 °C instead of a cup of water. The temperature of the oil increases to 27.33 °C . Calculate the mass of oil in the cup. The specific heat of copper is 0.387 J/g⋅°C and the specific heat of oil is 1.74 J/g⋅°C .
When the oil is added to the heated copper, the energy in the system is
conserved.
The mass of the oil in the cup, is approximately 64.73 grams.Reasons:
The question parameters are;
Temperature of the oil in the cup = 25.00°C
Final temperature of the oil and copper, T₂ = 27.33 °C
Specific heat of copper, c₂ = 0.387 J/(g·°C)
Specific heat capacity of oil, c₁ = 1.74 J/(g·°C)
Required:
The mass of oil in the cup.
Solution:
The mass of the copper, m₂ = 17.920 g
Temperature of copper after heating, T₂ = 65.17°C
Temperature of the copper after being placed in the cup of oil, T₂ = 27.33°C
Heat lost by copper = Heat gained by the oil
m₂·c₂·(T₂ - T₃) = m₁·c₁·(T₃ - T₁)Therefore, we get;
17.920 × 0.387 × (65.17 - 27.33) = m₁ × 1.74 × (27.33 - 25)
262.4219136 = 4.0542·m₁
m₁ ≈ 64.73
The mass of the oil in the cup, m₁ ≈ 64.73 gLearn more here:
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Possible part of the question obtained from a similar question online, are;
The mass of the copper, m₂ = 17.920 g
Temperature of copper after heating = 65.17°C
Construct a conclusion using the claim, evidence and reasoning format to explain the typical properties observed by ionic and covalent compounds.
Answer:
The key to understanding why ionic and covalent compounds have different properties from each other is understanding what's going on with the electrons in a compound. Ionic bonds form when atoms have different electronegativity values from each other. When the electronegativity values are comparable, covalent bonds form.
But, what does this mean? Electronegativity is a measure of how easily an atom attracts bonding electrons. If two atoms attract electrons more or less equally, they share the electrons. Sharing electrons results in less polarity or inequality of charge distribution. In contrast, if one atom attracts bonding electrons more strongly than the other, the bond is polar.
Ionic compounds dissolve in polar solvents (like water), stack neatly on each other to form crystals, and require a lot of energy for their chemical bonds to break. Covalent compounds can be either polar or nonpolar, but they contain weaker bonds than ionic compounds because they are sharing electrons. So, their melting and boiling points are lower and they are softer.
I hope this helps have a great day :)
How is hydrogen isolated from water
To extract hydrogen from water, researchers insert two electrodes across the water and pass current, which can separate the hydrogen from water. The process called electrolysis of water. ... An electric field applied through the cobalt oxide to water molecules resulted in the electrolysis of water
Hydrogen gas is an environment-friendly fuel — it produces water on combustion in the presence of oxygen. ... To extract hydrogen from water, researchers insert two electrodes across the water and pass current, which can separate the hydrogen from water. The process called electrolysis of water.
Using the combined gas
law, what is the final
volume of the Helium gas?
This is the answer i hope it helps
A sample of gas has Pi = 0.768 ATM, Vi = 10.5 L, and Ti = 300 K. What is the final pressure if VF = 7.85 L and T and f = 250 K?
What is the answer to this question?
Answer:i think its d not sure tho
Explanation:
Select all of the true statements about hydrocarbon structure.
a. Every hydrocarbon molecule is exactly the same as every other one.
b. The ability of carbon atoms to bond strongly to each other allows them to stably form ringed structures.
c. Hydrocarbons contain only single bonds that easily break down into smaller compounds.
d. Hydrocarbons are organic chemical compounds that consist of carbon and hydrogen.
Answer:
C
Explanation:
Organic compounds are the compounds which are made only from carbon and hydrogen. The correct option is option D that is hydrocarbons are organic chemical compounds that consist of carbon and hydrogen.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
There are two types of compound covalent compound and ionic in chemistry, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Hydrocarbons are organic compound. Hydrocarbon can have linear chain structure, ring structure or branched structure.
Therefore, hydrocarbons are organic chemical compounds that consist of carbon and hydrogen. The correct option is option D.
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HELP PLEASE I NEED THIS
What is the lowest point of a wave called?
Amplitude
Crest
Frequency
Trough
Answer:
the lowest point of the wave is called Trough
Answer:
Trough is the correct answer
Explanation:
The highest part of the wave is called the crest. The lowest part is called the trough.
how many nuetrons are in the nucleous of an atom number of 25?
Answer:
I believe there are 30
Explanation:
answer this please thank you
Answer:
Explanation:
D is the correct answer
A beaker containing a green liquid is left uncovered in a laboratory for one week., After the liquid evaporates, the beaker contains a dry green solid. Was the original liquid in the beaker an element, a compound, or a mixture?
The original liquid is regarded as a mixture.
A mixture is regarded as a material which comprises of two or more
substances which are combined physically. An example is the mixture of
dye and water.
A compound on the other hand is combined chemically and not physically
which when exposed to the same type of situation either remains in the
beaker or nothing at all is found. Since the water evaporates and a green
solid was present then it means the material was a solution in which
water(solvent) and the green solid(solute) was physically combined and not
chemically combined together.
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Problem 07.020 - Heat transferred from cold to hot reservoir Assume that heat in the amount of 100 kJ is transferred from a cold reservoir at 600 K to a hot reservoir at 1050 K contrary to the Clausius statement of the second law. What is the total entropy change
This problem is describing a system in which 100 kJ of energy is transferred from a cold reservior at 600 K to a hot one at 1050 K. This situation is opposed to the Clausius statement of the second law of thermodynamics, because it is widely known that heat is transferred from hot to cold systems.
However, we can calculate the total entropy change by using the following formula:
[tex]\Delta S =\Delta S _{Low}+\Delta S _{High}[/tex]
Which is broken down as follows:
[tex]\Delta S =\frac{-Q}{T_{Low}} + \frac{Q}{T_{High}}\\\\\\\Delta S =Q(\frac{-1}{T_{Low}} + \frac{1}{T_{High}})[/tex]
Since the heat is assumed to be equal for the both of them. Then, we plug in the given heat and temperatures to obtain:
[tex]\Delta S =100kJ(\frac{-1}{600K} + \frac{1}{1050K})\\\\\Delta S =-0.0714\frac{kJ}{K}[/tex]
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Question 11 pts
What is the term for the "invisible force" that holds you to Earth's surface?
Group of answer choices
gravity
mass
attraction
matter
Flag question: Question 2
Question 21 pts
Once an object is in motion, what type of energy is being used?
Group of answer choices
kinetic energy
gravity
potential energy
Flag question: Question 3
Question 31 pts
The Moon's mass is lower than that of Earth, thus its gravity is ____ Earth’s gravity.
Group of answer choices
less than
more than
the same as
Flag question: Question 4
Question 41 pts
When you roll a ball across a rug, what slows it to a stop?
Group of answer choices
Friction resists the ball’s forward motion.
The rug doesn’t have enough momentum to keep the ball rolling.
The rug doesn’t have enough force to keep the ball rolling.
The ball isn’t moving fast enough.
Flag question: Question 5
Question 51 pts
A championship swimmer swims 20 meters in 10 seconds. What is his speed?
Group of answer choices
20 m/s
2.0 m/s
0.5 m/s
200 m/s
Flag question: Question 6
Question 61 pts
Without an unbalanced force, an object will ____.
Group of answer choices
change its direction
maintain its velocity
stop moving altogether
change its speed
Flag question: Question 7
Question 71 pts
Which of the following indicates how fast something is moving?
Group of answer choices
speed
gravity
force
inertia
Flag question: Question 8
Question 81 pts
Which of Newton's laws is also known as the law of inertia?
Group of answer choices
Newton's third law
Newton's first law
Newton's second law
Flag question: Question 9
Question 91 pts
Which object would need the greatest force to overcome its inertia?
Group of answer choices
a sports car
a bicycle
a dump truck
a tennis ball
Flag question: Question 10
Question 101 pts
Which of the following is described by the change in an object’s position?
Group of answer choices
force
position
motion
Explanation:
gravity
kinetic energy
less than
friction resists the ball's movement
2.0 m/s
change its direction
speed
newton's first law
dump truck
position
Answer:
Q1 - Gravity
Q2 - Kinetic Energy
Q3 - Less than
Q4 - Friction resists the ball's forward motion
Q5 - 2 m/a
Q6 - Change its speed
Q7 - Speed
Q8 - Second law
Q9 - a dump truck
Q10 - motion
I am not sure about some answers but I answered all questions.
if you are a scientific or a inventor what do you want to discover or to invent relate to electrogmagnetism
Answer:
Michal Faraday 19th century
please Help me !! NO LINKS! fill this chemical reaction please
Answer:
see the above attachment.
Explanation:
hope this helps you.
3.00 L of a gas is collected at 35.0 C and 0.93 atm. What is the volume at STP
1. Which member of each pair is more stable? a. 2-Methyl-1-butene or 3-Methyl-1-butene b. 2-Methyl-1-butene or 2-Methyl-2-butene c. 2.3-dimethyl-1-butene or 2.3-dimethyl-2-butene
Answer:
c. 2-dimethyl-2-butene or 3-dimethyl-1-butene
what does cost-effective mean? im kind of confused on cost-effective and time-effective things and i keep getting mixed up :(
Cost-effective definition: producing good results without costing a lot of money. E.g: that machine is very cost effective, it made 200 shirts with only a dollar.
Time effective definition: how well time was used. E.g that machine is very time-effective, it made 200 pants in one hour!
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17.
In the reaction N2 + 3H2 → 2NH3 how many moles of ammonia will be produced from 1.30 mol
of hydrogen and excess nitrogen?
According to the equation given, we have N2 + 3H2 → 2NH3.
Therefore, to determine the moles of NH3 we have to do the following-
1.3 mol H2 × 2 mol NH3 / 3 mol H2 = 0.87 mol
Answer: .87 moles of NH3 are produced from 1.3 moles of H2.
I hope this helps!
Draw the other possible resonance structure of each organic ion. In each case, draw the structure that minimizes formal charges. Be sure to include all appropriate nonbonding electrons and charges. A three carbon chain with a double bond between carbons 1 and 2. Carbon 1 is bonded to two hydrogen atoms, carbon two is bonded to one hydrogen atom, and carbon three is bonded to two hydrogen atoms. There is a plus one charge on the third carbon atom. Draw the resonance structure of the allyl ion. A carbon atom is single bonded to a C H 3 group, double bonded to an oxygen atom, and single bonded to an N atom. The N atom is bonded to a hydrogen atom. It has two lone pairs and a minus one charge. The O atom has two lone pairs. Draw the resonance structure of the amidate ion.
Three resonance structures can be drawn for the allyl cation while two resonance structures can be drawn for the amidate ion.
Sometimes, we cannot fully describe the bonding in a chemical specie using a single chemical structure. In such cases, we have to use a number of structures which cooperatively represent the actual bonding in the molecule. These structures are called resonance or canonical structures.
The resonance structures of the allyl cation and the amidate ion are shown in the images attached to this answer. These structures show the different bonding extremes in these organic ions.
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How many grams of steam at 100 °C would be required to raise the temperature
of 47.6 g solid benzene (CH) from 5.5 °C to 30.0 °C? Assume that heat is only
transferred from the steam (and not liquid water) and that the steam/water and
benzene are separated by a glass wall and do not mix. (The melting point of ben-
zene is 5.5 °C; AHus for benzene is 9.87 kJ/mol; specific heat for benzene is 1.63
J/g• °C; AH for steam at 100 °C is 40.7 kJ/mol.)
vap
The mass of steam required to raise the temperature of water is 3.5 g.
The given parameters;
mass of the benzene, = 47.6initial temperature of the benzene, = 5.5 ⁰Cfinal temperature of the benzene = 30 ⁰CThe molar mass of Benzene = 78.11 g/mol
The molar mass of water = 18 g/mol
The number of moles of the Benzene is calculated as follows;
[tex]n = \frac{47.6}{78.11} = 0.61 \ mole[/tex]
The mass of steam required is calculated as follows;
heat lost by steam = heat absorbed by benzene
[tex]\frac{m}{18} \times 40.7 \times 10^3 = 47.6(1.63)(30-5.5) \ + \ 0.61 \times 9.87 \times 10^3\\\\2261.11 m = 7921.61\\\\m = \frac{7921.61}{2261.11} \\\\m = 3.5 \ g[/tex]
Thus, the mass of steam required to raise the temperature of water is 3.5 g.
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What does a chemical reaction tell us?
Answer:
A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. The properties of the products are different from those of the reactants.
I hope this helps.
How many moles of NaOH are present in 12.0 mL of 0.110 NaOH?
Moles: ___________
Answer:
0.00132moles
Explanation:
1000ml of NaOH contain 0.110 moles
12ml of NaOH contain (12*0.110)/1000 moles
= 0.00132 moles
HELP ME OUT PLEASE!!
Barium sulfate, BaSO4 is a white crystalline solid that is insoluble in water. It is used by doctors to diagnose problems with the digestive system,
Barium hydroxide, Ba(OH)2 is also a white crystalline solid and is used in wastewater treatment.
How many more oxygen atoms are represented in the formula for barium sulfate than in the formula for barium hydroxide?
A) 2
B) 4
C) 1
D) 8
Answer: 2
Explanation:
Ba(OH)2 contains two oxygen atoms
BaSO4 contains four oxygen atoms.
This means that barium sulfate contains two more oxygen atoms than barium hydroxide in its formula.
Hope this helps!! :)
According to formula BaSO₄, Barium sulfate contains 2 more oxygen atom.
The correct option is (A) 2
Barium sulfate's distinguishing featureBa(OH)₂ has two oxygen atoms in it.
Four oxygen atoms may be found in BaSO₄.
This indicates that the formula of barium sulfate has two extra oxygen atoms than the formula of barium hydroxide.
Barium sulfate, often known as BaSO4, is a transparent white pigment that has a long history. It is produced by combining sulfuric acid with barium hydroxide and other sources of barium.
Chemically speaking, barium hydroxide has the formula Ba(OH)2. The monohydrate of barium, sometimes referred to as baryta or baryta-water, is one of the element's main compounds. The typical commercial form of monohydrate is this white granular substance.
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Chemistry
Help me please.
Answer:
4:6
Explanation:
The pH of an acidic solution is 4.83. What is [H"]?
[tex]pH = -\log[H^{+}] \\\\\implies \log[H^{+}] = -pH\\\\\implies [H^{+}] = 10^{-pH}\\\\\implies [H^{+}] = 10^{-4.83} = 0.000015[/tex]
Imagine that you are toasting marshmallows using a metal stick over an open fire at your campsite.
Which of the following is the effect of radiation in this scenario?
Radiation causes heat to warm the entire campsite.
Radiation causes the metal stick to increase in temperature.
Radiation causes heat from the fire to warm the air.
Radiation causes hot air to move up to toast the marshmallow.
Answer:
Radiation causes the metal stick to increase in temperature.
Explanation:
Answer:
Radiation causes heat from the fire to warm the air.
Explanation:
cyclopropane is a commonly used anesthetic. If a 2.00 L flask contains 3.11 g of cyclopropane gas at 684 mmHg pressure and 23.0 C, what is the molecular mass of cyclopropane
Answer:
42.0g/mol
Explanation:
The steps for this question is to use the ideal gas law, and then use n=m/M to find molar mass.
PV = nRT
n= PV/RT
Change 23 degrees to 296.15 K and 684mmHg to kpa
n = (91.1925kpa)(2.00L)/(8.314Lkpa/mol K)(296.15K)
n= 0.074mol
n = m/M
M = m/n
M = 41.98489g/mol
HELP ME OUT PLEASE!!
Which model represents the chemical formula NO2, nitrogen dioxide?
A) A.
B) B.
C) C.
D) D.
Answer:
C
Explanation:
The answer is C, because nitrogen is in purple, and oxygen is in blue, and in NO2 you have 2 oxygen atoms.
In the laboratory you are asked to make a 0.282 m manganese(II) acetate solution using 315 grams of water. How many grams of manganese(II) acetate should you add
Answer:315 - 282 = 173?
Explanation:
