Question

1. how many protons do the following have? calcium gold copper iron 4. how many electrons do the following have? gold iron

Explanation:

Step1: Recall atomic number concept

The number of protons in an atom is equal to its atomic number.

Step2: Find atomic numbers

• The atomic number of gold (Au) is 79, so it has 79 protons.
• The atomic number of copper (Cu) is 29, so it has 29 protons.
• The atomic number of iron (Fe) is 26, so it has 26 protons.
• For a neutral atom, the number of electrons is equal to the number of protons. So gold has 79 electrons and iron has 26 electrons.

Answer:

Calcium: 20
Gold: 79
Copper: 29
Iron: 26
Gold (electrons): 79
Iron (electrons): 26