Fórmula (química)

The video explains that compounds are made of atoms combined in fixed ratios. It uses sodium chloride (NaCl) as an example, showing it always has one sodium atom for each chlorine atom. The video also describes water (H2O), highlighting that each molecule consists of two hydrogen atoms and one oxygen atom.

What is a defining characteristic of compounds?

• They consist of atoms in a fixed and specific ratio.

• They consist of atoms in a random ratio.

• They are made up of only one type of atom.

• They can change their composition easily.

What is the chemical formula for sodium chloride?

• NaCl

• H2O

• CO2

• O2

In sodium chloride, what is the ratio of sodium to chlorine atoms?

• One sodium atom for every two chlorine atoms

• Two sodium atoms for every chlorine atom

• One sodium atom for every chlorine atom

• Two chlorine atoms for every sodium atom

What is the chemical formula for water?

• H2O

• CO2

• NaCl

• O2

How many hydrogen atoms are in a molecule of water?

• One

• Two

• Four

• Three