U2Q2: The Atom

Front

What is the nucleus of an atom?

Back

The nucleus is the central part of an atom, containing protons and neutrons, and is responsible for most of the atom's mass.

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 determines the element's identity.

Front

How many protons are in an atom with an atomic number of 15?

Back

15 protons.

Front

What happens when an atom has more electrons than protons?

Back

The atom becomes an ion and is negatively charged.

Front

What does a +3 charge on an atom indicate?

Back

The atom has lost 3 electrons.

Front

What is the charge and mass comparison between protons and electrons?

Back

Electrons have an opposite charge to protons and a smaller mass.

Front

Define an ion.

Back

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Front

What is a neutral atom?

Back

A neutral atom has an equal number of protons and electrons, resulting in no overall charge.

Front

What is a mass number?

Back

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

Front

If an atom has a mass number of 31 and an atomic number of 15, how many neutrons does it have?

Back

16 neutrons (mass number - atomic number = neutrons).