$\mathrm{Na} \rightarrow \mathrm{Na}^{+} + e^{-}$

They have seven valence electrons and readily gain one to achieve a stable octet.

Question 1

Which of the following best explains why atomic radius increases as you move down a group in the periodic table?

Accepted Answer

Additional electron shells are added, increasing the distance between the nucleus and outer electrons.

Question 2

Which element would have the highest ionization energy among the following: Na, Mg, Al, or Si?

Accepted Answer

Si

Question 3

What is the trend for electronegativity as you move from left to right across a period?

Accepted Answer

Electronegativity increases due to greater effective nuclear charge.

Question 4

Which of the following best describes the reactivity of alkali metals?

Accepted Answer

They are highly reactive due to having one valence electron.

Question 5

Given the elements Mg and Sr, which has a larger atomic radius and why?

Accepted Answer

Sr, because it is lower in the same group and has more electron shells.

Question 6

Which of the following elements is most likely to form a negative ion?

Accepted Answer

Cl

Question 7

What is the general trend for ionization energy as you move down a group?

Accepted Answer

Ionization energy decreases due to increased distance from the nucleus and more shielding.

Question 8

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have a full valence shell, making them stable.

Question 9

Which element would have the greatest force of attraction between its nucleus and valence electrons: K, Ca, or Rb?

Accepted Answer

Ca

Question 10

A student compares the reactivity of Mg and Al. Which statement is correct?

Accepted Answer

Mg is more reactive because it is an alkaline earth metal and loses electrons more easily.

Question 11

Which of the following best describes the trend in metallic character as you move down a group?

Accepted Answer

Metallic character increases due to easier loss of electrons.

Question 12

Which element would have the highest conductivity: Na, Cl, or Ne?

Accepted Answer

Na

Question 13

Which of the following is the correct order of atomic radius from smallest to largest: O, F, N?

Accepted Answer

F < O < N

Question 14

Which of the following equations correctly represents the first ionization energy of sodium?

Accepted Answer

$\mathrm{Na} \rightarrow \mathrm{Na}^{+} + e^{-}$

Question 15

Which of the following elements is most likely to be malleable and conduct electricity?

Accepted Answer

Copper

Question 16

Which of the following best explains why halogens are highly reactive?

Accepted Answer

They have seven valence electrons and readily gain one to achieve a stable octet.

Question 17

Which element would have the lowest ionization energy: Li, Na, K, or Rb?

Accepted Answer

Rb

Question 18

Which of the following statements about periodic trends is correct?

Accepted Answer

Atomic radius decreases across a period due to increased nuclear charge.

Question 19

Which of the following elements is most likely to be found as a gas at room temperature and is chemically inert?

Accepted Answer

Argon

Question 20

A patient is exposed to a large amount of potassium. Which property of potassium makes it dangerous in high amounts?

Accepted Answer

It is highly reactive and can disrupt electrical signaling in the body.

Study Guide: Periodic Trends and Properties of Elements

Study Guide - Practice Questions