Periodic Table Basics

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which also equals the number of electrons in a neutral atom.

Front

How many protons and electrons does a boron atom have?

Back

A boron atom has 5 protons and 5 electrons.

Front

What is the maximum number of electrons that the first energy shell can hold?

Back

The first energy shell can hold up to 2 electrons.

Front

What is the maximum number of electrons that the second energy shell can hold?

Back

The second energy shell can hold up to 8 electrons.

Front

What is the maximum number of electrons that the third energy shell can hold?

Back

The third energy shell can hold up to 18 electrons.

Front

Who created the first periodic table?

Back

Dmitri Mendeleev created the first periodic table.

Front

What does the atomic number tell you about a neutral atom?

Back

The atomic number tells you the number of protons or electrons in a neutral atom of that element.

Front

How do you calculate the number of neutrons in an atom?

Back

To calculate the number of neutrons, subtract the atomic number (number of protons) from the atomic mass (rounded to the nearest whole number).

Front

What is the atomic mass of boron?

Back

The atomic mass of boron is approximately 10.811.

Front

What is the difference between protons and neutrons?

Back

Protons are positively charged particles found in the nucleus, while neutrons are neutral particles also found in the nucleus.