Chemical Bonding

Which of these elements is the most chemically reactive?

• Calcium (Ca)

• Radium(Ra)

• Beryllium (Be)

• Strontium (Sr)

How many valence electrons are in a neutral atom of Nitrogen (N)?

• 7

• 2

• 5

• 14

The alkali metal family of elements includes Li, Na, K, and Rb. These elements tend to easily form compounds with the halogens F, Cl, Br, and I. Which explains why they form compounds so easily?

• They have the same electron configuration as the halogens.

• They have seven electrons in their outer orbital which they readily lose.

• They have one electron in their outer orbital which attracts the protons in the halogen

  atoms.

• They have one electron in their outer orbital which they readily lose.

The position of an element on the periodic table helps scientists predict the number of electrons an atom will gain or lose during ion formation. According to the periodic table of the elements, which element is MOST likely to gain two electrons when it forms an ion?

• calcium (Ca)

• mercury (Hg)

• oxygen (O)

• iodine (I)

Based on the periodic table of the elements, which of these elements has properties MOST similar to calcium (Ca)?

• carbon (C)

• barium (Ba)

• Potassium (K)

• Scandium (Sc)

The noble gases, helium, neon, argon, krypton, xenon, and radon, rarely react with other elements because they

• have complete outermost energy levels.

• are low-density gases.

• are not abundant on Earth.

• have two electrons in their outermost energy level.

On the periodic table, helium (He) is placed at the top of group 18 (8A). What is the reason for helium being at this location on the periodic table?

• Helium is a very reactive gas.

• Helium loses its electrons easily.

• Helium is a transition metal.

• Helium has a filled outer energy shell.

How are potassium atoms and calcium atoms similar?

• Same number of valence electrons

• Same oxidation number

• Same number of energy levels

• Same number of protons

An element on the far left side of the PTE will have what property?

• A tendency to lose electrons when reacting.

• A tendency to avoid reactions.

• A tendency to gain electrons when reacting.

• A tendency to share electrons when reacting.

The table shows properties of several elements. Which element would Element X most likely be grouped (in a family) with on the PTE?

• Cl

• K

• B

• Cu