Helium (he) has two valence electrons, and these electrons are located in the 1s subshell. Without using the periodic table, in which group and period is helium located?.

Answers

Answer 1

helium is in group 8 and period 1


Related Questions

what is the name of the high-energy compound that cells use to fuel chemical reactions?

Answers

Answer: Adenosine triphosphate, or ATP, is the primary carrier of energy in cells. The water-mediated reaction known as hydrolysis releases energy from the chemical bonds in ATP to fuel cellular processes.

Explanation:

What is the differences between solids liquids and gases on a molecular level apes.

Answers

The difference is i dont know the answer i need points thank you

under the same conditions of temperature and pressure how does a liquid differ from a gas

Answers

Under the same conditions of temperature and pressure, a liquid differs from a gas because the particles of the liquid a) are in constant straight-line

How does a phase change from solid to liquid occur in a substance?(1 point)

Answers

Answer:

As heat is added to solid water, the temperature increases until it reaches 0 °C, the melting point. At this point, the phase change, added heat goes into changing the state from a solid to liquid. Only when this phase change is complete, the temperature can increase.

hope this helps

Heat is responsible for the change of phase from solid to liquid state.

A phase change from solid to liquid occur in a substance by heating of that substance because the bonds present between solid particles can be broken down with the help of heat energy.

When the bond is heat at the temperature on which it is broken down, the solid particles are converted into liquid substance so we can conclude that heat is responsible for the change of phase from solid to liquid state.

Learn more: https://brainly.com/question/25664350

A student dissolved some crystals of a salt in water.
The student added sodium hydroxide solution to the salt solution
The student added sodium hydroxide until it was in excess
Describe what the student would see if the salt contained calcium ions

Answers

That’s not nice you can’t be taking points

Under Normal Conditions no reaction will be seen between Calcium ions (Ca⁺), NaCl (salt solution) and NaOH(sodium hydroxide).

What is a double replacement reaction ?

In a double replacement reaction , the compounds present switch cation and anion to form new compounds.

But here in NaOH(sodium hydroxide) and NaCl (salt solution) the cation sodium ion Na⁺, of both the compounds is same so the end result will be same .

There will be no net reaction .

But if excess Sodium Hydroxide is added to the solution , we will see precipitate of NaCl , salt forming.

If Salt contained Ca⁺ ions , firstly NaCl will only combine with Ca⁺ ions in special conditions as Na⁺ ions are more reactive than Ca⁺ ions.

On addition of NaOH we would observe no change in normal conditions due to above stated reason .

In special conditions following reaction takes place ,in normal condition the reaction follows reverse direction.

Ca + 2 NaOH ← Ca(OH)₂ + 2 Na

Hence under Normal Conditions no reaction will be seen between Calcium ions , NaCl (salt solution) and NaOH(sodium hydroxide).

To know more about Double Displacement reaction

https://brainly.com/question/13870042

#SPJ2

Give 2 reason why cryolite is used

Answers

two reasons why cryolite is used in the electrolysis of aluminium oxide. The mixture of cryolite and aluminium oxide has a lower melting point than pure aluminium oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.

Give two reasons why cryolite is used in the electrolysis of ...https://www.mytutor.co.uk › answers › GCSE › Chemistry

which value represents the first ionization energy of a nonmetal

Answers

Answer:

increase in going from left to right across a given period.

Explanation:

Nonmetals, which are found in the right-hand region of the periodic table, have relatively large ionization energies and therefore tend to gain electrons. Ionization energies generally increase in going from left to right across a given period.

hope it is helpful:)

Describe how the suspects used the chemicals found at the crime scene to make the copper coins look silver.

Answers

The chemicals found at the crime scene although not mentioned must be Sodium zincate.

Discussion:

An interesting demonstration to show plating and alloys is the conversion of copper coins to silver look-alike coins.

A 'copper' coin when dipped into a solution of sodium zincate in contact with zinc. The coin is plated with zinc and appears silver in colour.

This is a common chemistry classroom trick.

Read more on plating:

https://brainly.com/question/20078989

Find the number of CO2 molecules present in 20l of CO2 at 0°C and 772mm of Hg.
I wiLL mark you as brainliest and give 50 points.​

Answers

Answer:

18

At STP, 22.4 liters of a gas forms one mole that is 6.023×10

23

molecules.

Volume of CO

2

in 1 litre of air =

100

0.03

×1 L

∴ No. of molecules of CO

2

=

22.4

6.023×10

23

×

100

0.03

=8.066×10

18

Explanation:

I guess it's this

R=8.314J/molKP=772mmHgT=0°C=273KV=20L

[tex]\\ \sf\longmapsto PV=nRT[/tex]

[tex]\\ \sf\longmapsto n=\dfrac{PV}{RT}[/tex]

[tex]\\ \sf\longmapsto n=\dfrac{772(20)}{8.314(273)}[/tex]

[tex]\\ \sf\longmapsto n=\dfrac{15440}{2269.722}[/tex]

[tex]\\ \sf\longmapsto n=6.8mol[/tex]

Why doesn’t one-electron transfer from a hydrogen atom to another hydrogen atom?

Answers

Answer:

The electrons start to repel each other.

Explanation:

Most atoms attain a lower potential energy when they are bonded to other atoms than when they are separated. One is that the single electrons that each hydrogen atom possesses begin to repel each other. This repulsive force would tend to make the potential energy of the system increase.

PLEASE HELP WILL MARK BRAINLIEST

Answers

Answer:

the answer is 150 in centimeters

what makes your pulse? Explain​

Answers

Blood flowing into and out your heart makes your pulse

mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron. carbon. plastic. glass.

Answers

Iron because iron is the only one magnetic of the three

Mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.

What is iron?

The chemical element iron has the atomic number 26 and the symbol Fe. It is a metal that is found in group 8 of a periodic table and the first transition series. It makes up a large portion of the planet's outer or inner core and is the most prevalent element on Earth by mass, just ahead of oxygen.

It is the fourth most prevalent element in the crust of the Earth, having been mostly deposited by meteorites inside its metallic state, along with its ores. Iron ores must be processed in kilns or furnaces that may reach 5000 °C (2,730 °F) and higher, which is approximately 500 °C (932 °F) greater than the temperature needed to smelt copper. Mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.

Therefore, mr. garcia uses magnets to hold a poster on a steel filing cabinet because a main component of steel is iron.

To know more about iron, here:

https://brainly.com/question/3299672

#SPJ7

determine the element of lowest atomic number that contains a complete d subshell in the ground state.

Answers

Answer:

The element with the lowest atomic number that contains a complete d-subshell in the ground state is copper.

Source:

Determine the element of lowest atomic number that contains a complete d subshell in the ground... - Study.com

type the max number of electrons that can be present in each shell or sub below

n = 5 shell __
n = 2 shell __
n = 2 l = 0 sub: __
n = 2 / 1 sub: __
3d sub: __
2s sub: __
5f sub: __

Answers

Explanation:

The maximum no. of electrons in a shell is given by. 2n^2 .

So for

n= 5 , 2× 5× 5 = 50

n=2 , 2×2×2 = 8

For a sub shell the maximum no. of electrons possible is given by 2(2l + 1)

So for n= l= 0

2 [(2×0) +1] = 2

for n=2 l=1

2 [(2×1) + 1] = 6

3d

d sub shell has l= 2 quantum number

Therefore 2[ (2×2) + 1] = 10

2s

s sub shell has l=0 quantum number

2 [(2×0) +1] = 2

5f

f sub energy level has l=3 quantum number

So 2[ (2×3) +1 ] = 14

The azimuthal quantum numbers for the sub shells are as follows

( s ---> 0

p----> 1

d----> 2

f ----> 3 )

put these atoms in order of increasing radius: Na, Mg,Cl, P

Answers

Answer:

Cl < P < Mg < Na

Explanation:

Cl must have the smallest radius because it is located to the right of the remaining elements on the same row. P  must have the second smallest radius because it is located to the right of the remaining elements on the same  row. Mg must have the Third smallest radius because it is located to the right of Na on the same row.  Therefore, Na has the Largest radius.

I hope it helps.

A solution containing cacl2 is mixed with a solution of li2c2o4 to form a solution that is 2. 1*10^-5m in calcium ion and 4. 75*10-5 m in oxalate ion. What will happen once these solutions are mixed?\.

Answers

Answer:

the answer is d

Explanation:

i know

Help ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:)

Answers

Correct:

Delivers Nutrients to cells Removes waste materials from cellsProtects the body from pathogensHelps cuts and wound to heal.

Incorrect:

Brings carbon dioxide to cells for use.

Carbon dioxide is the waste product of cells that you let out each time you breathe.

Which is the formula for nitrogen trihydride? NH3 N3H 3NH N3H3

Answers

the answer isssssssssssssssssssssss... Nh3.

Answer: A.) NH3

Explanation:

The diagram shows fertilization, the union of sperm cell and egg cell.



The traits of the offspring of the fertilized egg are coded onto
A
lipids in the offspring's cell membranes.

B
enzymes in the offspring's ribosomes.

C
genes in the offspring's chromosomes.

D
water in the offspring's mitochondrion.

Answers

The answer is C
You can start off by using process of elimination, we know that it is not D, and it is not A. This narrows it down to B and C, where we can see that C is the obvious answer, the genes in the chromosomes!

Which of these elements would have an electron affinity higher than that of oxygen?


Li
Ca
Ne
C
Be

Answers

Answer: Ne ( Neon )

Explanation: Lithium ( Li ), beryllium ( Be ), carbon ( C ), oxygen ( O ), and neon ( Ne ), are all in Period 2 in that order. Sodium ( Na ) is in Period 3. Since electron affinities decrease as you go down, Na would have a lower electron affinity level then Li but since electron affinities increase as you go across a period, only neon is farther right then oxygen ( O ), so it would be the only one element of this group that would have a higher electron affinity than that of oxygen.

There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.

What is periodic table?

Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.

Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.

On going down the group electronegativity decreases. On going along the period the electronegativity increases. So, Neon lies on the extreme right of Fluorine in the same period. Neon will have more electronegativity than oxygen.

Therefore, Neon is more electronegativity than fluorine.

Learn more about periodic table, here:

https://brainly.com/question/11155928

#SPJ2

how can teh human body looose heat? (conduction, convecion, radiation) and WHY

Answers

Answer:

Radiation and conduction

Explanation:

The human body lose heat by these two ways, because everything that touches our bodies and is in a temperature below us will receive part of our heat (conduction), and you can figure out that we lose heat by radiation because a human bright in a heat cam

Where do you think the atoms for plant growth come from?

Answers

Answer:

the mass of a tree is primary carbon

Explanation:

the the carbon comes from carbon dioxide during photosynthesis

Answer:

Plants get all the carbon, hydrogen, and oxygen they need from carbon dioxide and water, which they use to build carbohydrates during photosynthesis. To build other kinds of molecules they also need elements like nitrogen, phosphorous, and sulfur. Plants get these as well as other elements from the soil.

Explanation:

The half-life of a radioactive substance is 15 days. After 10 days a sample of the substance has been reduced to a mass of 4 mg. A. What was the inital mass (in mg) of the sample? B. Using your answer from above, after how many days will there only be 0. 3 mg of substance left?.

Answers

A. The initial mass of the sample is 6.35

B. The time taken for 0.3 mg of the sample to remain is 66 days

A. Determination of the initial mass of the sample

We'll begin by calculating the number of half-lives that has elapsed

Half-life (t½) = 15 days

Time (t) = 10 days

Number of half-lives (n) =?

n = t / t½

n = 10 / 15

n = ⅔

Finally, we shall determine the initial mass of the sample.

Number of half-lives (n) = ⅔

Amount remaining (N) = 4 mg

Initial amount (N₀) =?

[tex]N_0 = N \times {2}^{n} \\ N_0 = 4 \times {2}^{2 \div 3} \\ N_0 = 6.35 \: mg[/tex]

Therefore, the initial mass of the sample is 6.35 mg

B. Determination of the time

We'll begin by calculating the number of half-lives that has elapsed

Amount remaining (N) = 0.3 mg

Initial amount (N₀) = 6.35 mg

Number of half-lives (n) =?

[tex]{2}^{n} = \frac{N_0}{N} \\ \\ {2}^{n} = \frac{6.35}{0.3} \\ \\ {2}^{n} = 21.167 \\ take \: the \: log \: of \: both \: side \\ log \: {2}^{n} = log \: 21.167 \\ nlog2 = log \: 21.167 \\ divide \: both \: side \: by \: log2 \\ \\ n = \frac{log \: 21.167}{log2} \\ \\ n = 4.4[/tex]

Finally, we shall determine the time

Number of half-lives (n) = 4.4

Half-life (t½) = 15 days

Time(t) =?

t = n × t½

t = 4.4 × 15

t = 66 days

Therefore, it will take 66 days for 0.3 mg of the sample to remain.

Learn more: https://brainly.com/question/25749387

Chemistry help!!

A student conducts an experiment to separate water into hydrogen and oxygen as shown below.

As a result the student collects 28.0 g of hydrogen and 224.0 g of oxygen. How many grams water did the student originally have involved in the experiment

Answers

The student originally has 252 grams of water in this experiment.

LAW OF CONSERVATION OF MASS:

The law of conservation of mass explains that matter (mass) can neither be created nor destroyed but can be changed from one form to another.

This means that in a chemical reaction, the sum of the masses of the reactants must equate to the total mass of product(s).

According to this question, a student conducts an experiment to separate water into hydrogen and oxygen. The student collects 28.0 g of hydrogen and 224.0 g of oxygen.

Since hydrogen and oxygen are the constituent elements of water, the sum of their masses must equate the mass of water.

Therefore, 224g of oxygen + 28g of hydrogen = 252g of water.

Learn more at: https://brainly.com/question/24996173?referrer=searchResults

Violet light has a wavelength from 380 nm to 420 nm.
What velocity must a free electron have in order to exhibit the same wavelength as a violet photon with a
wavelength of 415 nm?

Answers

This question involves the concepts of de Broglie's wavelength and momentum.

The velocity of the electron must be "1754.27 m/s".

de Broglie's wavelength is a wavelength associated with a moving matter particle. It is connected to the momentum of the particle by the following formula:

[tex]P =\frac{h}{\lambda}\\\\mv=\frac{h}{\lambda}\\\\v=\frac{h}{m\lambda}\\\\[/tex]

where,

v = velocity of electron = ?

h = Plamk's Constant = 6.625 x 10⁻³⁴ J.s

m = mass of electron = 9.1 x 10⁻³¹ kg

λ = de Broglie's wavelength = 415 nm = 4.15 x 10⁻⁷ m

Therefrore,

[tex]v=\frac{6.625\ x\ 10^{-34}\ J.s}{(9.1\ x\ 10^{-31}\ kg)(4.15\ x\ 10^{-7}\ m)}[/tex]

v = 1754.27 m/s

Learn more about de Broglie's wavelength here:

https://brainly.com/question/20339737?referrer=searchResults

How to find formula for ionic compounds.

Answers

Answer:

I am using an example for this in this table it works for any other compound as well.

¿Cuáles son las características que presentan las enzimas? Explica cada una

Answers

Answer:

Acelera las reacciones químicas.

Se requieren en cantidades mínimas.

Son muy específicos en su acción.

Se ven afectados por la temperatura.

Se ven afectados por el pH.

Algunos catalizan reacciones reversibles.

Algunos requieren coenzimas.

Son inhibidos por inhibidores.

Explanation:

How do mixtures differ from substances?

Answers

Answer:

In chemistry: a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.

Hope this helps :)

A car starts from rest and accelerates at 2.5m/s^2 for 2s. What is the final velocity of the car

Answers

Question :-

A car starts from rest and accelerates at 2.5m/s² for 2s. What is the final velocity of the car?

Required Solution :-

The final velocity of the car is 5 m/s

Provided that :-

Acceleration, a = 2.5m/s²Time taken, t = 2 secInitial velocity, u = 0 m/s (As car started from rest)

To Calculate :-

The final velocity of the car

Required Equations of Motion :-

[tex]\begin{gathered}\boxed{\begin{array}{c}\\ {\pmb{\sf{Three \: equation \: of \: motion}}} \\ \\ \sf \star \: v \: = u \: + at \\ \\ \sf \star \: s \: = ut + \: \dfrac{1}{2} \: at^2 \\ \\ \sf \star \: v^2 - u^2 \: = 2as\end{array}}\end{gathered}[/tex]

Calculation :-

[tex]\pink{\qquad \pmb{ \sf\longrightarrow v \: = u \: + at}}[/tex]

[tex] \qquad \pmb{\sf \longrightarrow v = 0 + 2.5 \times 2}[/tex]

[tex]\qquad \pmb{ \sf\longrightarrow v = 0 + 5}[/tex]

[tex] \qquad \pmb{\sf \longrightarrow v = 5 \: ms^{-1}}[/tex]

[tex]\qquad \longrightarrow {\pink{\underline{\underline{\pmb{\sf{ Final \: velocity= 5 \: ms^{-1} }}}}}}[/tex]

Henceforth

The final velocity of the car is 5 m/s

▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬

Other Questions
Is the sentence below written in the active voice or passive voice?Nicole Watterson dreams of joining the circus.A. Active VoiceB. Passive Voice Saturns moon titan has a mass of 1.35 10^23 kg. if titan is 1.19 10^6 km from saturn, and saturns mass is 5.86 1026 kg, what is the gravitational force between saturn and its moon? Ella bought some keychains and spent a total of $24 each she can cost the same whole dollar amount. How many she bought between seven and 11 key chains. How many key chains did Ella buy? pls help asap! i will mark brainliest! Dark matter absorb light emit radiation and been observed directly. How would a child use addition to find 8 X 2? write a few sentences about the grand manner style and how it differed from mannerism? 4. What is our duty towards senior citizens? Write in 4 points What determines the price of goods in a free enterprise system?A. Supply and demandB. Agreement among producersC. Government agenciesD. Five-year plans Can me with the fill in the blanks please! Tell me which is the back and which is the front like which side is Donde estan and which is Que es estio! PLEASE do all of them for I will give no like or no brainest! So please do all and no links! Ty! Select the locations on the number line to plot the points 8/3 and 11/3. here are 20 employees in a company each employee worked 8 hours in a day and there a 5 days in week. In a particular week employees worked 1000 hours per week. The basis rate is $10 while overtime premium is paid time a half. Calculate the Total gross pay of the 20 employees of the week?$11500$12000$11000$13500 4. Find the mode of the set of data 12, 13, 18, 10, 13, 18, 12, 10, 18, 15. *1 point131015O18 Train car A is at rest when it is hit by train car B. The two cars, which have the same mass, stick together and move off after the collision. How does the final velocity of train cars A and B after the collision compare to the initial velocity of train car B before the collision?. 6.9 + (-5)+ 4.1=? Tell me if u go ogled trust me i know that u guys will i will not mark u brainliest if u lie that u di i can scan to see if u plagerized wat im saying is just tell me if u did im not gonna get mad lol i will get mad if u lie u di d it on ur own Why is tourism a service oriented industry? En la siguiente figura, determinar el valor de x.2x 3x Multiplications that give 48 as a result pls say the answer to me HELP!!! Los alumnos no ____________. Question 11 options: ensean la clase prestan atencin toman apuntes estudian