Question 1

Which of the following best describes the tendency of main group elements during chemical reactions?

Accepted Answer

They tend to achieve 8 valence electrons or a filled outer shell.

Question 2

When sodium (Na) forms a cation, which electron is removed first?

Accepted Answer

The electron from the 3s orbital.

Question 3

What is the condensed electron configuration for the Na$^+$ ion?

Accepted Answer

$1s^2 2s^2 2p^6$

Question 4

How many electrons must magnesium (Mg, atomic number 12) lose to obtain a filled outer shell?

Accepted Answer

2

Question 5

Which subshells are completely filled when an atom achieves the octet rule?

Accepted Answer

s and p

Question 6

What is the electron configuration for the Cl$^-$ ion?

Accepted Answer

$1s^2 2s^2 2p^6 3s^2 3p^6$

Question 7

Which statement correctly describes the process for writing the electron configuration of an anion?

Accepted Answer

Add electrons to the orbitals with available space.

Question 8

A main group metal typically forms a cation by:

Accepted Answer

Losing electrons to achieve the electron configuration of the noble gas before it in the periodic table.

Question 9

Which of the following is the correct electron configuration for the N$^{3-}$ ion?

Accepted Answer

$1s^2 2s^2 2p^6$

Question 10

When forming a cation, which principle is used to determine which electron is removed first?

Accepted Answer

The electron is removed from the highest principal quantum number (n).

Question 11

Which of the following best explains why non-metals gain electrons during chemical reactions?

Accepted Answer

To achieve the electron configuration of the noble gas after them in the periodic table.

Question 12

What is the electron configuration for a neutral sodium (Na) atom?

Accepted Answer

$1s^2 2s^2 2p^6 3s^1$

Question 13

Which of the following ions has the same electron configuration as neon (Ne)?

Accepted Answer

Na$^+$

Question 14

If an atom has the electron configuration $1s^2 2s^2 2p^6$, what is its charge if it originally had 7 electrons?

Accepted Answer

-3

Question 15

Which of the following is true about the stability of ions formed by main group elements?

Accepted Answer

Ions are most stable when they have completely filled s and p subshells.

Question 16

Which electron configuration represents a chloride ion (Cl$^-$)?

Accepted Answer

$1s^2 2s^2 2p^6 3s^2 3p^6$

Question 17

Which of the following is the correct order for filling electron orbitals according to the Aufbau principle?

Accepted Answer

$1s \rightarrow 2s \rightarrow 2p \rightarrow 3s \rightarrow 3p$

Question 18

A patient is found to have a blood sodium ion concentration higher than normal. Which electron configuration would you expect for the sodium ions in their blood?

Accepted Answer

$1s^2 2s^2 2p^6$

Question 19

Which of the following ions is isoelectronic with argon (Ar)?

Accepted Answer

Cl$^-$

Electron Configurations and the Octet Rule in Main Group Elements

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