Counting Atoms

What does the term 'molecule' refer to?

• A molecule is a single atom.

• A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

• A molecule is a type of chemical reaction.

• A molecule is a large structure made of many cells.

How many total atoms are in the compound 2NaCl?

• 2

• 3

• 4

• 5

What is the formula to calculate the total number of atoms in a molecule?

• Total atoms = sum of all subscripts in the chemical formula.

• Total atoms = number of elements in the formula.

• Total atoms = product of all subscripts in the chemical formula.

• Total atoms = average of all subscripts in the chemical formula.

How many atoms are in the compound 3H₂SO₄?

• 10 (5 Hydrogen + 3 Sulfur + 2 Oxygen)

• 12 (6 Hydrogen + 3 Sulfur + 12 Oxygen)

• 9 (3 Hydrogen + 3 Sulfur + 3 Oxygen)

• 15 (7 Hydrogen + 3 Sulfur + 5 Oxygen)

What is the total number of atoms in the molecule C₆H₁₂O₆ (glucose)?

• 20

• 22

• 24

• 26

What is the significance of coefficients in a chemical formula?

• Coefficients indicate the number of molecules or moles of a substance in a chemical reaction.

• Coefficients represent the temperature at which a reaction occurs.

• Coefficients are used to balance the charges in a chemical equation.

• Coefficients show the physical state of the reactants and products.

What does the term 'element' mean in chemistry?

• A substance that can be broken down into simpler substances by chemical means.

• A pure substance that cannot be broken down into simpler substances by chemical means.

• A mixture of two or more substances that retain their individual properties.

• A compound formed by the chemical combination of two or more elements.

In the formula MgSO₄, how many more Oxygen atoms are there than Magnesium atoms?

• 1

• 2

• 3

• 4

How many Oxygen atoms are in H₂O?

• 2

• 1

• 3

• 0

How many Hydrogen atoms are in 4H₂O?

• 4

• 6

• 8

• 10