Counting Atoms in Chemical Compounds

The video tutorial explains how to count the number of atoms in a compound, distinguishing it from counting elements. It provides examples using compounds like CO2, CaSO4, and NaOH, and offers practice problems to reinforce learning. The tutorial emphasizes the importance of recognizing numbers in chemical formulas to determine the number of atoms and clarifies that if no number is present, it implies one atom of that element.

What is the main focus when counting atoms in a compound?

• Counting the number of elements

• Counting the number of molecules

• Counting the number of bonds

• Counting the number of atoms

In the compound CO2, how many atoms of oxygen are present?

• Two

• One

• Four

• Three

If a compound has no number next to an element, how many atoms of that element are assumed to be present?

• Three

• Zero

• One

• Two

How many total atoms are in the compound CaSO4?

• Five

• Four

• Seven

• Six

In the compound NaOH, how many atoms are there in total?

• Two

• Five

• Three

• Four

How many atoms are in lithium nitrate (LiNO3)?

• Four

• Six

• Five

• Seven

In potassium hydroxide (KOH), how many atoms of hydrogen are present?

• Three

• Zero

• One

• Two

How many atoms are in sodium carbonate (Na2CO3)?

• Eight

• Six

• Five

• Seven

How many atoms are in beryllium oxide (BeO)?

• Three

• Two

• Four

• One

Why is O2 not considered a compound?

• It contains only one type of atom

• It has no chemical bonds

• It is not found in nature

• It is a gas