Front

What is the maximum number of electrons that can occupy the first energy level of an atom?

Back

2

Front

How many electrons are required to fill the second principal energy level of an atom?

Back

8

Front

What varies among atoms of the same element?

Back

mass number

Front

List the historical development of atomic models in order: hard indivisible sphere, mostly empty space, electron shells outside a central nucleus.

Back

B, C, A

Front

What part of the atom is indicated by an arrow pointing to it in a diagram?

Back

energy level

Front

What is the principal quantum number and what does it represent?

Back

The principal quantum number (n) indicates the energy level of an electron in an atom.

Front

What is the significance of the mass number in an atom?

Back

The mass number is the total number of protons and neutrons in the nucleus of an atom.

Front

What is the difference between an atom's atomic number and its mass number?

Back

The atomic number is the number of protons in the nucleus, while the mass number is the sum of protons and neutrons.

Front

What does the term 'electron configuration' refer to?

Back

Electron configuration describes the distribution of electrons in an atom's energy levels and orbitals.

Front

What is the shape of the s orbital?

Back

The s orbital has a spherical shape.