Yr10 Atomic Structure Test

Front

If an atom has 3 electrons, how many protons does it have?

Back

3 protons. In a neutral atom, the number of protons equals the number of electrons.

Front

A mole of helium contains _____ atoms.

Back

6.02 x 10^23 atoms. This is Avogadro's number, which defines the number of particles in one mole of a substance.

Front

All matter is made of what?

Back

Atoms. Atoms are the basic building blocks of matter.

Front

What is the number of nitrogen (N) atoms in (NH₄)₂CrO₄?

Back

2 nitrogen atoms. The formula indicates there are two ammonium ions, each containing one nitrogen.

Front

How many neutrons does the isotope of lithium have?

Back

5 neutrons. The most common isotope of lithium is Lithium-6, which has 3 protons and 3 neutrons.

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

Define a mole in chemistry.

Back

A mole is a unit of measurement that represents 6.02 x 10^23 particles, atoms, or molecules.

Front

What is the mass number of an atom?

Back

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

Front

What is the difference between an atom and a molecule?

Back

An atom is the smallest unit of an element, while a molecule is a group of two or more atoms bonded together.

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.