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IrinaK [193]
3 years ago
6

Use the periodic table to identify the number of core electrons and the number of valence electrons in each case below. Potassiu

m (K): 1s22s22p63s23p64s1
Chemistry
2 answers:
ss7ja [257]3 years ago
8 0

Answer:

The number of core electrons = 18 electrons.

The number of valence electrons = 1 electron.

Explanation:

  • The core electrons are the electrons in the inner shells (1s²2s²2p⁶3s²3p⁶).

∴ the number of core electrons = 18 electrons.

  • The valence electrons are the electrons in the outermost shell (4s¹).

∴ the number of valence electrons = 1 electron.

Bess [88]3 years ago
8 0

Answer:

18 core electrons

1 valence electron

Explanation:

In the periodic table, potassium stands at the head or beginning of the fourth period. It is found in group 1. The third period ends with argon having 18 electrons. This implies that potassium should have at least 18 core electrons. Since it is found in group 1 having only 1 valence electron, it is expected to also have one valence electron.

Its electron configuration summarizes these statements above; 1s22s22p63s23p64s1

There are 18 core electrons and one valence electron in the outermost 4s1 orbital (the fourth shell)

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What does in the zone mean in a picture and a idiom? (Please answer this as soon a possible!)
julia-pushkina [17]
If you are in the zone, you are happy or excited because you are doing something very skilfully and easily.
5 0
3 years ago
What is the concentration (in M) of a 225ml potassium sulfate solution that contains 4.15g of potassium?
mars1129 [50]

The concentration of solution in M or mol/L can be calculated using the following formula:

C=\frac{n}{V} .... (1)

Here, n is number of moles and V is volume of solution in L.

The molecular formula of potassium sulfate is K_{2}SO_{4} thus, there are 2 moles of potassium in 1 mol of potassium sulfate.

1 mol of potassium will be there in 0.5 mol of potassium sulfate.

Mass of potassium is 4.15 g, molar mass is 39.1 g/mol.

Number of moles can be calculated as follows:

n=\frac{m}{M}

Here, m is mass and M is molar mass

Putting the values,

n=\frac{(4.15 g}{(39.1 g/mol}=0.1061 mol

Thus, number of moles of  K_{2}SO_{4} will be 0.1061\times 0.5=0.053 mol.

The volume of solution is 225 mL, converting this into L,

1 mL=10^{-3}L

Thus,

225 mL=0.225 L

Putting the values in equation (1),

C=\frac{(0.053 mol}{0.225 L}=0.236 M

Therefore, concentration of potassium sulfate solution is 0.236 M.


4 0
3 years ago
How many core electrons are in a ground state atom of selenium?
Harman [31]
Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.

Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;

                          1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴

From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So, 

             Core Electrons  =  Total Electrons - Valence Electrons

             Core Electrons  =  34 - 6

             Core Electrons  =  28

Result:
          There are 28 core electrons in Selenium.
3 0
3 years ago
Is the answer B? Help
Masja [62]

Answer:

A

Explanation:

Hmm, so we have the following in the diagram

Pt(s)

Cl2(g)

Ag(s)

NaCl(aq)

AgNO3(aq)

Pt 2+, 4+, 6+  Though it states Pt is inert

Cl 2-

Ag 1+

Na 1+

NO3-

Anode definition: the positively charged electrode by which the electrons leave an electrical device.

Electrode definition: a conductor through which electricity enters or leaves an object, substance, or region.

Cations attracted to cathode pick up electrons

Anions attracted to anode release electrodes+

Reduction at Cathode (red cat gain of e)

Oxidation at Anode (ox anode loss of e)

So from the diagram we can see that the charge is being generated through the 2 metal plates.

So the answer is A, the anode material is Pt and the half reaction is 2Cl- = Cl2 + 2e-

7 0
2 years ago
3Fe+4H2O(yields) Fe3O4+4H2. What is the mole ratio of Fe3O4 to Fe?
WINSTONCH [101]

<u>Answer:</u> The correct answer is Option A.

<u>Explanation:</u>

Mole ratio is defined as the ratio between the stoichiometric coefficients of the molecules present in the chemical reaction.

For the given balanced chemical equation:

3Fe+4H_2O\rightarrow Fe_3O_4+4H_2

By Stoichiometry of the reaction:

3 moles of iron metal reacts with 4 moles of water to produce 1 mole of iron oxide and 4 moles of hydrogen gas.

The mole ratio of Fe_3O_4:Fe=1:3

Hence, the correct answer is Option A.

7 0
2 years ago
Read 2 more answers
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