can someone please explain core and valence electrons in periods for me please​

Answers

Answer 1

Answer:

The electrons of an atom are typically divided into two categories: valence and core electrons. Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels

Explanation:

i hope u get it :))


Related Questions

Electronegativity6. Which one of the following bonds is the least polar one?
options:

C-F
C-Cl
C-Br
C-I

Answers

I think C-I

It can also be wrong but that’s my opinion

help me with this attachment please​

Answers

Answer:

See explanation

Explanation:

Let us recall that the basic rule in writing balanced chemical reaction equations is that the number of atoms of each element on the right hand side of the reaction equation is the same of the number of atoms of the same element on the left hand side of the reaction equation.

The reaction of red hot iron and steam is written as follows;

3Fe + 4H2O → Fe3O4 + 4H2.

The decomposition reaction of ammonium dichromate is written as;

(NH4)2Cr2O7 → N2 + Cr2O3 + 4H2O

Reaction of aluminium, sodium hydroxide and water is as follows,

2Al + 2NaOH + 2H2O ----> 2NaAlO2 + 3H2

Reaction of potassium bicarbonate with sulphuric acid;

2KHCO3 + H2SO4 -------> K2SO4 + 2H2O + 2CO2

Reaction of zinc and sodium hydroxide is as follows;

Zn + 2NaOH→Na2ZnO2 + H2

A sample of gas occupies a volume of 55.3 L, has a temperature of 23.3 °C and a pressure of .658 atm. Calculate the number of moles of gas which are present in the sample. R= .0821 atm L/mol K

Answers

Answer: The number of moles of gas which are present in the sample are 1.49 mol.

Explanation:

Given: Volume = 55.3 L

Temperature = [tex]23.3^{o}C[/tex] = (23.3 + 273) K = 296.3 K

Pressure = 0.658 atm

Formula used is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]PV = nRT\\0.658 atm \times 55.3 L = n \times 0.0821 L atm/mol K \times 296.3 K\\n = \frac{0.658 atm \times 55.3 L}{0.0821 L atm/mol K \times 296.3 K}\\= \frac{36.3874}{24.32623}\\= 1.49 mol[/tex]

Thus, we can conclude that the number of moles of gas which are present in the sample are 1.49 mol.

How does an indicator show the difference between an acid and an alkali?​

Answers

Answer: There are various indicators like litmus paper, phenolphthalein, universal indicator etc. that changes its colour to show the difference between acid and alkali.

What is the mass of 0.125 moles of tin sulfate (SnSO4)?

Answers

Answer:

26.85 grams

Explanation:

The formula for mole calculations is number of moles = given mass/gram-formula mass.

The number of moles is given to us, which is 0.125.

The gram formula mass of SnSO4 is about 214.77.

Plug in the values we have into the equation. It should look like this:

0.125 = x / 214.77

Solve for x by multiplying 214.77 and 0.125. The answer should be about 26.85 grams.

Why does platinum metal make a good catalytic surface for reactant molecules?
It causes reactant molecules to be less reactive.
It strengthens bonds between reactant molecules.
It prevents products from breaking away from the surface.
It holds reactant molecules in a good position for them to react.

Answers

Answer:

it holds reactant molecules in a good position for then to react

Answer:

D. It holds reactant molecules in a good position for them to react.

Explanation:

Got a 100 on e2020.

In what way are electrons quantized?
O A. They have fixed energy values.
they
OB. They can be gained and lost.
O C. They are negatively charged.
O D. They form bonds in molecules.

Answers

Answer: The correct option is A) They have fixed energy values.

Explanation:

Electron is one of the sub-atomic particle present around the nucleus of an atom which is negatively charged.

In an atomic model, it is assumed that the electron revolves around the nucleus in discrete orbits having fixed energy levels.

These electrons when jumping from one energy level to another, some amount of radiation is either emitted or absorbed.

These fixed energy levels are given by the Bohr model and thus, the electrons are quantized.

Hence, the correct option is A) They have fixed energy values.

Answer: They have fixed energy values

Explanation: a pex

How does dissolving a salt molecule in water make its atoms ionize?

Answers

Answer:

It's take 1 and a half hours

Explanation:

Ugbdunvisrtg

Thompson's experiments with cathode ray tube lead to the invention of what?

Answers

Answer:

Thompson's experiments with cathode ray tube showed that every atom contains a small amount of negatively charged subatomic particles. Thomson proposed the plum pudding model of the atom.

Explanation:

Which of these is a measure of the average kinetic energy of the molecules of a material? A.heat B.temperature C.thermal energy D.bonding energy

Answers

Answer:

b temperature

Explanation:

Temperature is a measure of the average kinetic energy of the particles in a substance

Please I need an explanation on the relationship between concentration and volume of reacting substances​

Answers

Answer:

when d volume of a substance is high, the concentration is gonna b low...

Jus lyk putting much water in just a cube of sugar

Explanation:

So lower volume, higher concentration

What is the ratio of sodium ion to phosphate ion
in the formula Na3PO4?

Answers

Answer:

42,07%and 18,90%

Explanation:

A molecule has four bonded atoms around a central atom. The central atom does not have any lone pairs of electrons. What is the geometry of the molecule?

Answers

Answer:

Tetrahedral. Tetra- signifies four, and -hedral relates to a face of a solid; “tetrahedral” literally means “having four faces. ” This shape is found when there are four bonds all on one central atom, with no lone electron pairs. In accordance with the VSEPR theory, the bond angles between the electron bonds are 109.5o ...

There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the geometry of given molecule is tetrahedral.

What is VSEPR theory?

VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.

According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element.

A molecule has four bonded atoms around a central atom. The central atom does not have any lone pairs of electrons. The geometry of such molecule is Tetrahedral. Geometry does not include lone pair on central atom.

Therefore, the geometry of given molecule is tetrahedral.

To know more about VSEPR theory, here:

https://brainly.com/question/19582124

#SPJ6

Which best describes an alpha particle that is emitted during nuclear decay?

A. A helium nucleus
B. A hydrogen nucleus
C. An electron
D. A positron

Answers

Answer:

A helium nucleus

Thre types of radiation

Alpha: Helium nucleus

Beta: Electron

Gamma: Gamma rays

E. Give reasons
1. Oxygen is a diatomic element.
3. The valency of sodium is one.
F. Differentiate between
1. electrovalent bond and covalent bond
2. acidic radical and basic radical​

Answers

Answer:

the valency of sodium is one because sodium loses 1 electron to become stable

2. Evaluate :
(i) 28 : 23​

Answers

Answer:

28/23

Explanation:

28 : 23

this is written as ,

28/23

u can convert into simplest form but in this question u can't so leave it as it is.

Diseña un procedimiento que te ayudaría a obtener agua en el desierto usando como fundamento la destilación?

Answers

Answer:b

Explanation:

I searched it

Cheese is an example of Solid in gas colloid Liquid in gas colloid Solid in liquid colloid Liquid in solid colloid

Answers

The solution in which the solute particles are suspended in a liquid (fluid) is called colloidal solution. Colloid is a solution that has particles ranging between 1 and 1000 nanometres. Cheese is a solid emulsion in which liquid is solute and solid is solvent. Hence, cheese is colloidal solution of liquid in solid.

Calculate the change in thermal energy when 2kg of water is heated from 20°C to 80°C.​

Answers

Answer:

504000 J

Explanation:

Applying,

Δq = cm(Δt)............. Equation 1

Where Δq = change in thermal energy, c = specific heat capacity of water,  m = mass of water, Δt = change in temperature.

From the question,

Given: m = 2 kg, Δt = 80-20 = 60°C

Constant; c = 4200 J/kg.°C

Substitute these values into equation 1

Δq = 2(4200)(60)

Δq = 504000 J

Hence the thermal energy is  504000 J

what does the second law of thermodynamics say about entropy

Answers

Answer:

The entropy and the systems surrounding it tend to increase.

Answer: The entropy in a system and its surroundings tends to increase.

Explanation:

3.3.2 Quiz: Entropy (a p e x)

m%of solution containing 100 gram of NaCl dissolved in 500g of water

Answers

Answer:

16.7 %(m/m)

Explanation:

The percent by mass of a solution (% m/m) is defined as 100 times the ratio of the mass of solute (The substance in the lower amount, NaCl) and the mass of the solution = Mass solute + Mass Solvent (water).

Mass Solution:

100g NaCl + 500g water = 600g solution

Mass Percent:

100g NaCl / 600g solution * 100

= 16.7 %(m/m)

Which group on the periodic table contains chemical elements that are shiny and conduct electricity?
A.
Metalloids
B.
Nonmetals
C.
Representative elements
D.
Metals

Answers

D. Metals
Elements that are shiny, solid, conducts electricity, has atomic mass of 108 is metal.

Complete the table by writing the name or formula of each compound and the type of bonding that it uses. You may refer to this list of polyatomic ions.

Answers

Explanation:

Dinitrogen monoxide: covalent bond

copper(||) hydroxide: ionic bond

Butane: Covalent Bond

Answer

Disulfur decafluoride S2F10 covalent

calcium sulfide  CaSO3 ionic

Diphosphorus tetraiodide P2I4 ionic

dinitrogen monoxide  N2O   ionic

Aluminum chloride  AlCl3  covalent

copper(II) hydroxide  Cu(OH)2  ionic

barium sulfate BaSO4  covalent

butane  C4H10  covalent

Explanation:

edmentum

Calculate the number of O atoms in 0.364 g of CaSO4 · 2H2O

Answers

Answer:

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

Explanation:

For problems like this posting, one needs an understanding of the following topics:

The definition of the mole

1 mole of substance = mass in grams of substance containing 1 Avogadro's Number ( = 6.023 x 10²³ ) of particles of the specified substance. This is generally one formula weight of the substance of interest. From this, the following equivalent relationships should be memorized:

  1 mole = 1 formula weight = 1 mole weight (g)= 6.023 x 10²³ particles

Converting grams to moles:

Given grams => moles = grams/gram formula wt

Converting moles to grams:

Given moles => grams = moles x gram formula wt

_________________________________________________________

Calculate the number of O atoms in 0.364 g of CaSO₄ · 2H₂O.

Given mass CaSO₄ · 2H₂O = 0.364 grams

Formula Wt CaSO₄ · 2H₂O = 172 g/mole

moles CaSO₄ · 2H₂O = mass CaSO4 · 2H2O / formula Wt. CaSO₄ · 2H₂O

= 0.364 g CaSO₄·2H₂O / 172 g CaSO4·2H2O

= (0.364/172) mole CaSO₄·2H₂O

= 2.12 x 10⁻³ mole CaSO₄·2H₂O    

∴ number of Oxy (O) atoms in 0.364 grams CaSO₄·2H₂O

=  (2.12 x 10⁻³ mole CaSO₄ · 2H₂O)(6.023 x 10²³ molecules CaSO₄· 2H₂O/ mole)

= 1.276876 x 10²¹molecules CaSO₄· 2H₂O  CaSO₄2H₂O

= 1.276876 x 10²¹ molecules CaSO₄· 2H₂O   x   6 oxygen atoms / molecule

= 7.661256 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

What is a molecule containing only carbon and hydrogen called?
O A. An inorganic molecule
O B. A hydrocarbon
O c. A metallic molecule
D. An ionic molecule
(answer is provided) :)

Answers

Answer:

A

Explanation:

did that on my test

A. It’s A bc the girl answered it before so I believe A

Can someone please solve this for me and explain it

Answers

83.3% yield

Explanation:

First, we need to convert 240 g of [tex]Fe_{2}O_{3}[/tex] into moles:

[tex]240 \:g \:Fe_{2}O_{3} \:\times(\frac{1\:\text{mol}\:Fe_{2}O_{3}}{159.69\: \text {g}\:Fe_{2}O_{3}})[/tex]

[tex]=1.50 \:\text{mol}\:Fe_{2}O_{3}[/tex]

Next, find the theoretical Fe yield using molar ratios.

[tex]1.50 \: \text {mol} \: Fe_{2}O_{3}\: \times (\frac{2\: \text{mol} \: Fe}{1 \:\text{mol} \: Fe_{2}O_{3}})[/tex]

[tex] = 3.00 \: \text{mol} \: Fe[/tex]

Then convert this back into grams:

[tex]3.00 \: \text{mol} \:Fe \times (\frac{55.845 \: \text{g} \: Fe}{1 \: \text{mol} \: Fe}) = 168 \: \text{g} \: Fe[/tex]

Note that actual yield is only 140 g Fe so percentage yield is

[tex]\dfrac{140\:\text{g}\:Fe}{168\:\text{g}\:Fe} \times 100[/tex]%= 83.3%

83.3%

The answer is 83.3%

BRAINILIEST PLEASE

Rob measures the solubility of three different salts in water at 22°C.

Which type of graph should he use to display his data?

Answers

Answer:

He should use a bar graph

Explanation:

Since this is a distinction between three very distinct categories a bar graph should be perfect

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Answers

Chrctv yn ynwynqrbevr

Which statement is true for most autotrophic organisms?
A. They carry on extracellular digestion of nutrients before they ingest them.
B. They synthesize organic molecules from inorganic molecules.
C. They obtain organic molecules from heterotrophic organisms.
O O
D. They require no external energy source.

Answers

omg yees

eExplanation:

I have oxygen gas at 2 L and 2 atm. At what pressure is the oxygen gas if my volume decreases to 1 L?

Answers

Answer: The oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.

Explanation:

Given: [tex]V_{1}[/tex] = 2 L,        [tex]P_{1}[/tex] = 2 atm

[tex]V_{2}[/tex] = 1 L,          [tex]P_{2}[/tex] = ?

Formula used to calculate the new pressure is as follows.

[tex]P_{1}V_{1} = P_{2}V_{2}[/tex]

Substitute the values into above formula as follows.

[tex]P_{1}V_{1} = P_{2}V_{2}\\2 atm \times 2 L = P_{2} \times 1 L\\P_{2} = 4 atm[/tex]

Thus, we can conclude that the oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.

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