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

If 200 mL of a gas at 27 °C is cooled to -33 °C at a constant pressure, the volume will be

Answers

Answer:

V2 = 159.48 mL

Explanation:

Given the following data;

Initial volume = 200 mL

Initial temperature = 28°C

Final temperature = -33°C

To find the final volume, V2, we would use Charles law;

First of all, we would convert the temperature in Celsius to Kelvin.

Mathematically, it is given by the formula;

Kelvin = 273 + C

Substituting into the equation, we have;

Initial temperature, T1:

Kelvin = 273 + 28

Kelvin = 301K

Initial temperature, T1:

Kelvin = 273 - 33

Kelvin = 240K

To find new volume V2, we would use Charles' law.

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles is given by;

[tex] VT = K[/tex]

[tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Where;

V1 and V2 represents the initial and final volumes respectively.

T1 and T2 represents the initial and final temperatures respectively.

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

Making V2 as the subject formula, we have;

[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]

[tex] V_{2}= \frac{200}{301} * 240[/tex]

[tex] V_{2}= 0.6645 * 240 [/tex]

V2 = 159.48 mL

an organism that gains energy by feeding on other organism is a
A. consumer
B. predator
C. prey
D. parasite
F. host

Answers

Answer: the answer is A

Explanation:

Answer:

The answer to your question is, A. consumer.

Explanation:

Any organism that 'consumes' other organisms is a consumer

Help needed ASAP, I will mark your answer as brainly.

Answers

Answer


E. 21.3mmHg is the right answer

Please help me I will really appreciate it !!!! And Please no links

Write a clear scientific explanation of how and why the water ended up on the mirror and not in the tub. Be sure to include scientific vocabulary (including any phase changes that occurred and the role of kinetic energy).

The Vocabulary words-
Condensation
Gas
Heat
Kinetic energy
Liquid
Steam
Vaporization
Water vapor

Answers

Explanation:

Steaming up or fogging happens when steam condenses on the mirror. Steam emerging from hot water can condense on a colder surface. That’s the reason you can see the result on a mirror instantaneously. Obviously, for a bathroom mirror to steam up, the steam that originates at the shower spray (or the bathtub) has to travel through the cooler air to reach the mirror. Since air tends to heat up easily, the mirror can steam up fast.

A student carried out a titration using HC2H3O2(aq)HC2H3O2(aq) and NaOH(aq)NaOH(aq). The net ionic equation for the neutralization reaction that occurs during the titration is represented above. The NaOH(aq)NaOH(aq) was added from a buret to the HC2H3O2(aq)HC2H3O2(aq) in a flask. The equivalence point was reached when a total of 20.0mL20.0mL of NaOH(aq)NaOH(aq) had been added to the flask. How does the amount of HC2H3O2(aq)HC2H3O2(aq) in the flask after the addition of 5.0mL5.0mL of NaOH(aq)NaOH(aq) compare to the amount of HC2H3O2(aq)HC2H3O2(aq) in the flask after the addition of 1.0mL1.0mL of NaOH(aq)NaOH(aq), and what is the reason for this result

Answers

Answer:

The amount of HC₂H3₃2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.

Explanation:

Equation of the reaction between acetic acid, HC₂H₃O₂(aq) and sodium hydroxide, NaOH(aq) is given below:

CH₃COOH (aq) + NaOH (aq) ----> CH₃COONa (aq) + H₂O

The equation of the reaction shows that acetic acid andsodium hydroxide will react in a 1:1 ratio

Since the concentration of NaOH was not given, we can assume that the concentration is 0.01 M

Moles of NaOH in 5.0 mL of 0.01 M NaOH = 0.01 × 5/1000 = 0.00005 moles

Moles of NaOH in 1.0 mL of 0.01 M NaOH = 0.01 ×1/1000 = 0.0001 moles

Ratio of moles of NaOH in 5.0 mL to 1.0 mL = 0.00005/0.00001 = 5

There are five times more moles of NaOH in 5.0 mL than in 1.0 mL and this means that 5 times more the quantity of HC₂H₃O2(aq) required to react with 1.0 mL NaoH is needed to react with 5.0 mL NaOH.

Therefore, the amount of HC₂H₃O2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.

What is the molality of a solution containing 19.5g HCl and 257g of H2O?

Answers

m= 2.06

molality is m = moles/kg

if you look at the periodic table the mass of HCl is 36.458 rounded to 36.5

divide the 19.5g by the mass (36.5) and you’ll get 0.53

next, you convert g to kg so you divide by 1,000. 257/1,000 = 0.257

you plug those two answers into the equation > m= 0.53 mol HCl/ 0.257kg H20

the answer will be 2.06 when you divide and there’s how you get the molality.

remember, HCl is the solute and H20 is the solvent.

In an alternation of generations life
cycle, the gametophyte is part of which
generation?

Answers

Answer:

The sexual phase, called the gametophyte generation, produces gametes, or sex cells, and the asexual phase, or sporophyte generation, produces spores asexually. In terms of chromosomes, the gametophyte is haploid (has a single set of chromosomes), and the sporophyte is diploid (has a double set

Answer:

Gametophyte generation

Mr. Ragusa is approached in his lab by one of his students named Hassan. Hassan had found a bottle of nitric acid that did not have a labeled molarity and wanted Mr. Ragusa to help him find it's molarity. Mr. Ragusa filled a buret to 4.85 mL with 0.30 M NaOH. Mr. Ragusa added 5 mL of the acid to a flask and added some phenolphthalein. Mr. Ragusa hit the titration spot on, and the final volume in the buret was 43.69 mL. What is the concentration of the Nitric Acid?
Round your answer to 2 decimal places. Include a unit in your answer. (ex: 1.2M)
HNO3 + NaOH --> NaNO3 + H2O

Answers

Answer:

2.33M

Explanation:

1. First, make sure the equation is balanced. In this case it would be HNO3+NaOH --> NaNO3 + H2O. (it is already balanced here.)

2. Find the initial volume, final volume, the volume of acid, volume of NaOH.

      a. Initial Volume: 4.85 mL

      b. Final Volume: 43.69

      c. Acid (HNO3) Volume: 5 mL

      d Volume NaOH: Initial V - Final V --> 43.69 mL - 4.85 mL = 38.84 mL NaOH

3. Find moles of NaOH reacted using the volume from D. Convert this volume into Liters. Multiply the volume of NaOH by molarity of NaOH given to you before. (.30 M NaOH)

      a. x mol NaOH/ .03884 L = .30 mol NaOH/ 1 mol = .011652 mol NaOH

4. Now find the moles of acid. The acid given to you in the equation is HNO3. The .011652 mol NaOH is from the moles reacted that you just found. The moles on the right side would be the co-efficient in front of the elements in the equation. Since this equation does not have any coefficients (it's already balanced), it would just be 1.

      a.  .011652 mol NaOH/ x mol HNO3 = 1 mol NaOH/ 1 mol HNO3.

                       x = .011652 mol HNO3

5. Now find the concentration, also known as molarity. Divide the .011652 mol by the volume of acid you have been given (5 mL). Before using 5 mL, divide it by 1000 to get the Liter form.

     a. .011652 mol HNO3/ .005 L = 2.3304 M HNO3

I hope you understand now. God bless!


Calculate the volume in L of 11.6 moles of Neon at 120 K when it has a pressure of 25.9 atm

Answers

Answer:

The volume of the gas is approximately 4.41 liters

Explanation:

The details of the data of the Neon gas are;

The number of moles of Neon gas present, n = 11.6 moles

The temperature of the sample of Neon gas, T = 120 K

The pressure of the sample of the Neon gas, P = 25.6 atm

By the ideal gas equation, we have;

P·V = n·R·T

Where;

R = The universal gal constant = 0.08205 L·atm·mol⁻¹·K⁻¹

Therefore, we get;

V = n·R·T/P

Which gives;

V = 11.6 moles × 0.08205 L·atm·mol⁻¹·K⁻¹ × 120 K/(25.9 atm) ≈ 4.4097915 L

The volume of the gas, V ≈ 4.41 L.

Which statement is true in comparison to a weak acid, a strong acid
has a larger ph than weak acids
is more concentrated than we gases
strong acids produced less H plus ions is mostly H plus ions in solution

Answers

Answer: Strong acid vs weak acid

Strong acids and strong bases refer to species that completely dissociate to form ions in solution.

Explanation: By contrast, weak acids and bases ionize only partially, and the ionization reaction is reversible. Thus, weak acid and base solutions contain multiple charged and uncharged species in dynamic equilibrium.

What type of cell can pass a DNA mutation to an organism's offspring?
A. sex cell
B. skin cell
c. nerve cell
D. red blood cell

Answers

The answer should be sex cell.

which of the following can not be guessed about the prehistoric organism by its fossil ?

Answers

Answer:

Evolution in the broadest sense explains that what we see today is different from what existed in the past. Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.Something that happened in the past is thus not "off limits" for scientific study. Hypotheses can be made about such phenomena, and these hypotheses can be tested and can lead to solid conclusions. Furthermore, many key aspects of evolution occur in relatively short periods that can be observed directly—such as the evolution in bacteria of resistance to antibiotics.Laws, like facts and theories, can change with better data. But theories do not develop into laws with the accumulation of evidence. Rather, theories are the goal of science.

Explanation:


How many moles of hydrogen gas
are produced when 3.8 moles of HCI
are reacted?
O 1.9 mol

Answers

1.9 mol H2.
3.8 mol HCl * (1 mol H2 / 2 mol HCl) = 1.9 mol H2

What is the concentration of a sodium hydroxide solution if 14.5 mL of it are exactly neutralized by 30.0 mL of a 0.500 M hydrochloric acid solution?

Answers

Answer:

1.03 M

Explanation:

Step 1: Write the balanced equation

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the reacting moles of HCl

30.0 mL (0.0300 L) of 0.500 M HCl react.

0.0300 L × 0.500 mol/L = 0.0150 mol

Step 3: Calculate the moles of NaOH that react with 0.0150 moles of HCl

The molar ratio of NaOH to HCl is 1:1. The moles of NaOH that react are 1/1 × 0.0150 mol = 0.0150 mol.

Step 4: Calculate the molar concentration of NaOH

0.0150 moles of NaOH are in 14.5 mL (0.0145 L).

M = 0.0150 mol/0.0145 L = 1.03 M

Which reactant is necessary for a combustion reaction?
A. Water
O B. Heat
O c. Carbon dioxide
D. Oxygen

Answers

The reactant necessary for a combustion reaction is oxygen.

(option D).

Combustion is a chemical reaction that occurs when a substance reacts with oxygen, producing heat and light. In order for combustion to take place, three elements are needed: fuel, heat, and oxygen.
Fuel is the substance that undergoes combustion, such as gasoline, wood, or methane. Heat is the energy required to initiate and sustain the reaction. Lastly, oxygen is the reactant that combines with the fuel, allowing it to burn and release energy.
When a combustion reaction occurs, the fuel and oxygen combine to form carbon dioxide (option C) and water (option A). This process is exothermic, meaning it releases energy in the form of heat and light.
For example, when wood is burned in the presence of oxygen, it undergoes combustion. The heat from a match or a spark provides the necessary activation energy to start the reaction. Oxygen from the air combines with the carbon in the wood, producing carbon dioxide and releasing energy in the form of heat and light.
In summary, oxygen is the reactant necessary for a combustion reaction. It combines with the fuel and releases energy in the form of heat and light.

(option D).

For more such questions on combustion reaction

https://brainly.com/question/13251946

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What type of reaction occurs when one element or ion within a compound is exchanged with another element or ion?
combustion
decomposition
single-displacement
double-displacement

Answers

Answer:

When an element replaces another in aone element or ion within a compound is exchanged with another element or ion , the reaction is called 

single-displacement

How many grams of iron oxide, Fe2O3 will be produced if 165 g of O2 gas is supplied? (follow the same steps as mol to mol, only now your flow should be like this: grams O2 moles O2  moles Fe2O3  grams Fe2O3 Fe + O2  Fe2O3

Answers

Answer:

[tex]m_{Fe_2O_3}=549gFe_2O_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction for this problem about stoichiometry:

[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]

Whereas there is a 3:2 mole ratio of oxygen (molar mass = 32.0 g/mol) to iron (III) oxide (molar mass = 159.69 g/mol) and therefore, the correct stoichiometric setup is:

[tex]m_{Fe_2O_3}=165gO_2*\frac{1molO_2}{32.00gO_2}*\frac{2molFe_2O_3}{3molO_2} *\frac{159.69gFe_2O_3}{1molFe_2O_3} \\\\m_{Fe_2O_3}=549gFe_2O_3[/tex]

Regards!

____CH4 + ____O2  ____CO2 +____H2O

Answers

[tex]methane \: reacts \: with \: oxygen [/tex]

CH4 + 2O2 → CO2 + 2H2O.

Step-by-step explanation

L.H.S.

C = 1, H = 4, O = 2×2 = 4.

R.H.S

C = 1, O = 2, H = 2×2= 4, O = 2.

whoever answeres all the questions will get brainliest question

question 1
why is steel not a mineral?
A. is it man-made

B. is it alive

c. is it found in nature

d. is it strong

question 2
which mineral is used to make pencils?

A. diamond

B. jade

c. graphite

d. calcite

question 3
wich mineral is used to make glass

A. emerald

b. quartz

c.copper

D. halite

question 4
wich mineral do we eat

A. silver

b. jade

c. quartz

d.halite

question 4 _____ is the hardest mineral and ____ is the softest

A. quartz, graphite

B. silver, gold

C. diamond , talc

d. halite, calcite

question 5
what is minerals streak

A. the color minerals streak

b. how much the mineral weighs

c. the shape of crystals

d. the color left behind when a mineral is
scraped on porcelain tile

question

question 6
all minerals break at the same time

a. true

b. false

Answers

Answer:

1. A

2. C

3. B

4. D

5. D

6. B

Explanation:

I'm not quiet sure on 5 but I'm pretty sure its correct

A __________ is a feature or some influence that contributes to a result or outcome.

factor

theory

light year

spectrograph

Answers

it’s A or factor big homie g

Which of the changes listed below would shift this reaction to the right?


A. Decrease of pressure

B. Addition of Cl2

C. Removal of O2

D. Increase of pressure

Answers

Answer:

D: Increase of pressure

A 3.5L container has a gas pressure of 5.3atm. If the volume is decreases to 1.4L. What will be the new pressure inside the container?​

Answers

Answer:

your answer for that problem is 34.5

34.5 it’s so easy lol like try

What is the number of moles of solute in 250 mL of a 0.4M solution?
a. 0.1 mol
c. 0.62 mol
b. 0.16 mol
d. 1.6 mol

Answers

Explanation:

Answer. There are 0.1 moles of solute in 250 mL of 0.4 M solution.

188 grams of Ca(OH)2 contain how many moles?(with calculations)

Answers

Report this clown who put the first answer he’s trying to get your ip

Please help im testing and need an answer as soon as possible

Kaya collects the data shown in the table.

A 2-column table with 3 rows. The first column labeled Quantity has entries Voltage, Current, Resistance. The second column labeled Value has entries 6.0 volts, 0.3 Amperes, empty.

What is the resistance in the circuit?
0.05
1.8
5.7
20

Answers

Answer:

20

Explanation:

not sure please correct me if im wrong

Answer:

20

Explanation:

Got it right on time 4 learning

If the kinetic and potential energy in a system are equal, then the potential energy increases. What happens as a result?

Answers

Answer: As a result an increase in kinetic energy also happens.

Explanation:

Potential energy is the energy occupied by an object or substance due to its position.

Kinetic energy is the energy occupied by an object of substance due to its motion.

If the kinetic and potential energy in a system are equal and then an increase in potential energy will occur.

As a  result, there will also occur an increase in kinetic energy also.

Thus, we can conclude that as a result an increase in kinetic energy also happens.

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 does atom mean
A.)Consists of only electrons
B.)The smallest part of matter still retaining chemical properties
C.)Consists of only protons and neutrons
D.)Composed of two or more separate elements

Answers

Answer:

B). The smallest part of matter still retaining chemical properties.

what might happen if the strong force didnt exist

Answers

If the strong force didn't exist, there would be nothing but hydrogen and neutrons floating in space. ... When the protons and neutrons are apart there is no strong force but when they are together to resemble a nucleus, the strong force is in action.

Answer:

Atomic nuclei would fly apart

Explanation:

What is the MOST important advantage of using ethanol as a fuel
for vehicles?
A. Ethanol reduces air pollution.
B. Ethanol mixes well with gasoline.
C. Making ethanol uses up plant products.
D. Making ethanol provides income for growers.

Answers

Answer:

The correct answer is - A. Ethanol reduces air pollution.

Explanation:

Ethanol is believed to be better fuel for the environment than other petroleum fuels. Ethanol emits lower carbon dioxide as it is clean smokeless fuel, and produces less or the same oxides of nitrogen and hydrocarbons.

It is produced by the process of fermentation of molasses by yeast. Mixing it with the other fuels is found to be CO2 reduces by 30% of emissions to the atmosphere.

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