Helium only has two valence electrons and is a stable atom. How is this possible when atoms
need 8 valence electron to become stable?

Answers

Answer 1

Answer:

Explanation:

Helium (He) is similar in that it, too, only has room for two electrons in its only valence shell. Hydrogen and helium have only one electron shell. The first shell has only one s orbital and no p orbital, so it holds only two electrons. Therefore, these elements are most stable when they have two electrons.


Related Questions



How many pairs of electrons are shared by adjacent carbon atoms in an alkane?

Answers

Answer:

one

Explanation:

So, the number of pair of electrons are shared between two adjacent carbon atoms in a saturated hydrocarbon is 1

How many grams would be in 1.752 x10^26 formula units of Ca(No3)2

Answers

Answer:

47730 grams.

Explanation:

First we convert 1.752x10²⁶ formula units of Ca(NO₃)₂ into moles, using Avogadro's number:

1.752x10²⁶ formula units ÷ 6.023x10²³ formula units/mol = 290.88 mol

Then we convert 290.88 moles of Ca(NO₃)₂ into grams, using the molar mass of Ca(NO₃)₂:

290.88 mol * 164.088 g/mol = 47730 g

True or False?

When it is summer in the Northern Hemisphere, it is summer all around the word

Answers

True.................

What is the name of this hydrocarbon?

Answers

Answer:

2,3-dimetylpentane

Explanation:

.....................

A balloon contains 25.0 L of helium gas at 177 kPa. What is the volume when the balloon rises to an altitude where the pressure is only 43.0 kPa ? Assume the temperature remains constant.

A.34.2 L
B.68.8 L
C.46.5 L
D.103 L

Answers

I think answer is D not sure

Type the correct answer in the box. Express your answer to three significant figures. Iron(II) chloride and sodium carbonate react to make iron(II) carbonate and sodium chloride: FeCl2(aq) + Na2CO3(s) → FeCO3(s) + 2NaCl(aq). Given 1.24 liters of a 2.00 M solution of iron(II) chloride and unlimited sodium carbonate, how many grams of iron(II) carbonate can the reaction produce? The reaction can produce grams of iron(II) carbonate.

Answers

Answer:

Explanation:

To solve this problem we have to find the moles of iron(II) chloride that react. Using the chemical equation, we can kknow moles FeCl2 = Moles FeCO3. Thus, we can find the moles of FeCO3. Converting these moles to grams using its molar mass -Molar mass FeCO3: 115.854g/mol-

Moles FeCl2 = Moles FeCO3:

1.24L * (2.00mol / L) = 2.48 moles FeCl2

Mass FeCO3:

2.48mol * (115.854g / mol) =

The reaction can produce 287 grams of iron(II) carbonate

Answer:

its 287

Explanation:

i got it right on edm

What is the density of an object that has a mass of 350 g and a volume of 95 cm?? Would
this object float in water?

Answers

Answer:

Density= 3.68g/cm³

The object will sink in water

Explanation:

D=m/v

=350/95

=3.684

≈3.68g/cm³

Water= 1g/cm³

The object will sink in water because the object is denser than the water.

3.684g/cm³ is the density of an object that has a mass of 350 g and a volume of 95 cm³. The object will sink in water.

What is density?

The density of a material (volumetric density and specific mass) is its mass per unit volume. The most common sign for density is however the Roman letter D can be used as well. Density is defined mathematically as mass divided with volume.

The density of a pure material has the same numeric values just like its mass concentration. Various materials have varied densities, and density can be important in terms of buoyancy, purity, and packing.

D=m/v

=350/95

=3.684g/cm³

The object will sink in water

Therefore, 3.684g/cm³ is the density of an object that has a mass of 350 g and a volume of 95 cm³. The object will sink in water.

To learn more about density, here:

https://brainly.com/question/29775886

#SPJ2

PLEASE HELP.
What does the atomic number of an element tell us?
A) the number of neutrons in an atom of an element
B) the number of protons in an atom of an element
C) the number of protons, electrons, and neutrons in an element

Answers

The actual answer is B, the number of protons in an atom of an element :)

PLS HELP ME WILL GIVE BRAIN THINGYYYYY

Answers

Answer:

C, when the ball lands it will have the least amount potential energy.

Explanation:

here is a picture that should help you.

The shape of the methane molecule(ch4) is called

Answers

Answer:

Tetrahedral

Explanation:

A compound contains 1.2 g of carbon, 3.2 g of oxygen and 0.2g of hydrogen. Find the formula of the compound

Answers

Answer:

The empirical formula of the compound is [tex]C_{0.504}HO_{1.008}[/tex].

Explanation:

We need to determine the empirical formula in its simplest form, where hydrogen ([tex]H[/tex]) is scaled up to a mole, since it has the molar mass, and both carbon ([tex]C[/tex]) and oxygen ([tex]O[/tex]) are also scaled up in the same magnitude. The empirical formula is of the form:

[tex]C_{x}HO_{y}[/tex]

Where [tex]x[/tex], [tex]y[/tex] are the number of moles of the carbon and oxygen, respectively.

The scale factor ([tex]r[/tex]), no unit, is calculated by the following formula:

[tex]r = \frac{M_{H}}{m_{H}}[/tex] (1)

Where:

[tex]m_{H}[/tex] - Mass of hydrogen, in grams.

[tex]M_{H}[/tex] - Molar mass of hydrogen, in grams per mole.

If we know that  [tex]M_{H} = 1.008\,\frac{g}{mol}[/tex] and [tex]m_{H} = 0.2\,g[/tex], then the scale factor is:

[tex]r = \frac{1.008}{0.2}[/tex]

[tex]r = 5.04[/tex]

The molar masses of carbon ([tex]M_{C}[/tex]) and oxygen ([tex]M_{O}[/tex]) are [tex]12.011\,\frac{g}{mol}[/tex] and [tex]15.999\,\frac{g}{mol}[/tex], then, the respective numbers of moles are: ([tex]r = 5.04[/tex], [tex]m_{C} = 1.2\,g[/tex], [tex]m_{O} = 3.2\,g[/tex])

Carbon

[tex]n_{C} = \frac{r\cdot m_{C}}{M_{C}}[/tex] (2)

[tex]n_{C} = \frac{(5.04)\cdot (1.2\,g)}{12.011\,\frac{g}{mol} }[/tex]

[tex]n_{C} = 0.504\,moles[/tex]

Oxygen

[tex]n_{O} = \frac{r\cdot m_{O}}{M_{O}}[/tex] (3)

[tex]n_{O} = \frac{(5.04)\cdot (3.2\,g)}{15.999\,\frac{g}{mol} }[/tex]

[tex]n_{O} = 1.008\,moles[/tex]

Hence, the empirical formula of the compound is [tex]C_{0.504}HO_{1.008}[/tex].

an organism that a parasite lives in or on is a
A. prey
B. host
C. consumer
D. prey

Answers

i believe it’s d, hope this helps!
The answer is B, hope this helps!

how to balance _h2s+ _o2 = _h2o+ _s

Answers

Answer:

2H₂S + 1O₂ → 2H₂O + 2S

Explanation:

SOLUTION :-

Balance it by using 'hit & trial' method , and you'll get the answer :-

2H₂S + 1O₂ → 2H₂O + 2S

VERIFICATION :-

In reactant side of equation :-

Number of atoms in H = 2×2 = 4Number of atoms in S = 2×1 = 2Number of atoms in O = 1×2 = 2

In product side of equation :-

Number of atoms in H = 2×2 = 4Number of atoms in O = 2×1 = 2Number of atoms in S = 2×1 = 2

Number of atoms of each element is equal in both reactant & product side of equation. Hence , the equation is balanced.

2.14g of sodium sulfide react with excess hydrochloric acid to form sodium chloride and dihydrogen sulfide.
BALANCE IT TO AN EQUATION

Answers

Answer:

2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S

Explanation:

The Balanced equation is

Na2S + 2HCl = 2NaCl + H2S

As we can see -

78.0452 g/mol of sodium sulfide reacts with 2 mole of HCl.

Mass of one mole of HCl = 36.458 g/mol

So, 78.0452 g/mol of sodium sulfide reacts with 2* 36.458 g/mol of HCL to produce 2* 58.44 g of NaCl and 34.1 g/mol of H2S

Thus,

2.14g of sodium sulfide will react with (2* 36.458/78.0452)* 2.14 of HCl

2.14g of sodium sulfide will react with 1.99 g of HCl

2.14 Na2S + 1.99 HCl ----> (2* 58.44/78.0452) *2.14 NaCl + (34.1/78.0452) * 2.14 H2S

2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S

A 3.20-mol sample of gas occupies a volume of 350. mL at 300.0 K. Determine the

pressure of the gas.

Answers

Answer:

[tex]P \approx 225atm[/tex]

Explanation:

From the question we are told that:

Moles of sample n=3.20_mol

Volume V=350mL

Temperature T=300k

Generally the equation for ideal gas is mathematically given by

 [tex]PV=nRT[/tex]

 [tex]P=\frac{nRT}{V}[/tex]

 [tex]P=\frac{3.20*0.08206*300}{350*10^{-3}}[/tex]

 [tex]P=225.079atm[/tex]

 [tex]P \approx 225atm[/tex]

why should Asus be stores only in the glass containers please answer this ​

Answers

Answer:

Do you mean acids?

Due to chemical reaction

Explanation:

Acids are only stored in glass containers because glass containers rarely react with any substance.They dont react with acids and prevent chemical reaction so the acids can be kept. If acids were kept in metal containers it would react .

20. Which of the following is the correct name for N205?
O nitrate oxide
O dinitrogen pentoxide
O nitrous oxide
O nitrogen dioxide

Answers

Answer: N205 is dinitrogen pentoxide

Answer:

B!

Explanation:

Di stnds for 2 (N2)

pent = 5 (05)

Which are three ways water reaches the atmosphere?
A. sublimation, condensation, transpiration
B. evaporation, radiation, and condensation
C. transpiration, evaporation, and sublimation

Answers

Answer:

C. Transpiration, evaporation, and sublimation.

Explanation:

thank you to the internet.

C .....................

When you mix water and salt you get a. ​

Answers

Salt water , from the ocean

Find the molality of a solution of 58.5 g NaCl dissolved in 0.556 kg of water

Answers

Answer:lmk

Explanation:

I really need help please someone help me?!.

Those are all the questions.

Answers

Answer:

question two is most likely you can describe the shape as a twisted ladder, thats what I learned in school.

Explanation:

YW

Sorry I couldn’t help

If 10.5 g of iron, at 25°C, absorbs 128 J of heat, what will be the final temperature of metal? (The specific heat of iron is 0.449 J g-1 °C-1)

Answers

Answer:

27.5°C = Final Temperature of the metal

Explanation:

The change in temperature using the specific heat of a material could be obtained using the formula:

Q = m*S*ΔT

Where Q is heat absorbed in Joules = 128J in the problem

m is the mass of the substance = 10.5g

S is Specific Heat of the substance = 0.449J/g°C for Iron

ΔT is change in temperature = Final T - Initial T

Replacing:

128J = 10.5g*0.449J/g°C*ΔT

2.5°C = ΔT

2.5°C = Final T - 25°C

27.5°C = Final Temperature of the metal

How much energy is required to raise the temperature of a 300.0

gram block of lead from 22.3°C to 59.9°C? The specific heat of lead is

0.129 J/gºC.

Answers

Answer:

Q = 1455.12 Joules.

Explanation:

Given the following data;

Mass = 300 grams

Initial temperature = 22.3

Final temperature = 59.9°C

Specific heat capacity = 0.129 J/gºC.

To find the quantity of energy;

[tex] Q = mcdt[/tex]

Where,

Q represents the heat capacity.

m represents the mass of an object.

c represents the specific heat capacity of water.

dt represents the change in temperature.

dt represents the change in temperature.

dt = T2 - T1

dt = 59.9 - 22.3

dt = 37.6°C

Substituting the values into the equation, we have;

[tex] Q = 300*0.129*37.6 [/tex]

Q = 1455.12 Joules.

Mention any two uses of oxygen gas.​

Answers

Answer:

steel, plastics

Explanation:

Hope it helps!

Why are scientists using acoustic surveys to learn about rainforest diversity

Answers

Answer:

Acoustic survey data can help inform scientists about the locations of the rainforest with the highest biodiversity. ... By working with these companies, The Nature Conservancy can help inform them of where they might try to create wildlife corridors or connected habitats on their lands

What product is formed when sodium and chlorine undergo a synthesis reaction? sodium chlorite
sodium chlorate
sodium and chloride
sodium chloride

Answers

Sodium chloride is the answer
Sodium chloride is formed

select all that are heterogeneous mixtures.
A) soil
B) steel
C) concrete
D) kool-aid
E) open can of soda

Answers

Soil, concrete, and an open can of soda are all heterogeneous mixtures

The individuality of an organism is
determined by the organism's
A) amino acids
B) DNA nucleotide sequence
C) nitrogenous bases
D) transfer RNA molecules

Answers

I think is B sorry if I’m wrong

For the combustion of acetaldehyde, CH2CHO, there is 42L at STP and 79g of Oz. How much water is produced? ​

Answers

52L bc it makes sense

Hydrologers study the availability of fresh water on the planet.

Answers

Answer:

Hydrologists study how water interacts with the earth's crust. For example, they may study how rainfall and snowfall cause erosion, create caves, percolate through soil and rock to become groundwater, or eventually reach the sea.Hydrologists strive to improve water quality and increase our access to water so that we can continue to make use of it in all the ways that are necessary to our lives. A hydrologist measures the stream flow in a tributary to the Coeur d'Alene River. layers of gases surrounding a planet or other celestial body

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