1. Sodium and potassium have similar chemical and physical properties. This is b

Question

1.

Sodium and potassium have similar chemical and physical properties. This is best explained by the fact that both elements

A.have low relative atomic masses.

B.are in Period 1 of the periodic table.

C.have relatively low first ionization energies.

D.have the same ground-state valence-electron configuration.

E.are active metals.

2.

Which of the following statements is true concerning the electron configuration [Ne]3s13p1?

A.It may represent a ground-state electron configuration of a Al+ cation.

B.It may represent an excited-state electron configuration of a Mg atom.

C.It may represent an excited-state electron configuration of a Ne– anion.

D.It may represent a ground-state electron configuration of a Na+ cation.

E.It may represent a ground-state electron configuration of a Mg+ cation.

3.

Which of the following subshells does not exist?

A.3p

B.3f

C.6g

D.4d

E.2s

4.

Sodium oxide reacts with water to produce sodium hydroxide. Suppose 10.2 g of sodium oxide is combined with 34.6 g of water. When the reaction is complete, all the sodium oxide has been consumed. According to the law of conservation of mass, which is a true statement?

A.The mass of sodium hydroxide produced plus the mass of unreacted water must equal 44.8 g.

B.The mass of sodium hydroxide produced must equal 10.2 g.

C.The mass of water consumed must equal 10.2 g.

D.The mass of sodium hydroxide produced must equal 44.8 g.

E.The mass of unreacted water must equal 24.4 g.

Explanation / Answer

1). The elements having similar property are come under same groups so the answer for this is

B. ) Are in period 1 of the periodic table.

2). Atomic number of Mg is 12

Ground state electronic configuration of Mg is

[Ne] 3S2

Excited state electronic configuraiton: When elecron from 3S jumps to 3P :

[Ne] 3S1 3P1

So the answer is :

B. It may represent the excited state electronic configuraiton of Mg atom.

3. )

f subshell starts from principle number 4 and so 4 f is not possible

and answer is :

B. 3f

4)

The reaction is Na2O + H2O -- > 2NaOH

Accoring to the mass conservation mass of reactants = mass of products.

Total mass of reactant = 10.2 + 34.6 = 44.8 g

And so statement D is correct.

Ans D. The mass of sodium hydroxide produced must equal to 44.8 g

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