Week 5 Review: Isotopes, Periodic table and reactivity

What is the mass number of this atom?

• 7
• 14
• 21
• none of the above

Elements that lie along the stair-step line of the periodic table are

• metals.

• liquids.

• radioactive.

• metalloids.

How many valence electrons does the element have?

• 1

• 2

• 3

• 4

What does D represent on an element box?

• Element name

• Element symbol

• Atomic Number

• Atomic Mass or Mass Number

Poor conductor of heat and electricity is a property of _________

• metals

• metalloids

• nonmetals

What are the seven chemical elements that make up Group 18?

• Nobel gases

• Bloom gases

• Metalliods

• Liquid Gases

These elements have properties of both metals and nonmetals.

• Metalliods

• Metals

• Gases

• Nonmetals

What is the mass number of a beryllium atom that has 3 neutrons?

• 4

• 7

• 9

• 3

How many hydrogen atoms are present in one molecule of ammonium acetate, NH₄C₂H₃O₂?

• 7

• 11

• 4

• 3

A horizontal row of elements in the periodic table

• Molecule

• Period

• Family

• Atom