GCSE (9-1) Chemistry - Assessment 1

Atomic Structure, Periodic Table, Chemical Bonds, Chemical Reactions, Sates of Matter,

What is an atom?

A basic unit of matter.

What are protons, neutrons, and electrons?

• Protons: positively charged particles in the nucleus.

• Neutrons: neutral particles in the nucleus.

• Electrons: negatively charged particles surrounding the nucleus.

What is the charge of a proton?

+1

What is the charge or a neutron?

0 (neutral)

What is the charge of an electron?

-1

Where are protons and neutrons located in an atom?

In the nucleus.

What is the atomic number?

The number of protons in an atom.

What is the mass number?

The total number of protons and neutrons in an atom.

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

Mass number - atomic number = number of neutrons.

What are isotopes?

Atoms of the same element with different numbers of neutrons.

How do isotopes differ from each other?

They have different mass numbers but the same atomic number.

What is an ion?

An atom that has gained or lost electrons and has a charge.

How does the number of electrons determine the charge of an atom?

• More electrons than protons = negative charge (anion).

• More protons than electrons = positive charge (cation).

What is the Periodic Table?

A table organizing all known elements based on atomic number and properties.

What do the groups in the Periodic Table represent?

Columns indicating elements with similar properties.

What do the periods in the Periodic Table represent?

Rows indicating elements with the same number of electron shells.

What is the significance of the noble gases?

They are inert and have full outer electron shells.

What are transition metals?

Elements found in groups 3-12 known for their ability to form variable oxidation states.

What is the reactivity trend in the alkali metals?

Increases down the group.

How does temperature affect reaction rates?

Higher temperatures increase reaction rates by providing more energy to particles.

What are the three main states of matter?

Solid, liquid, gas.

How does temperature affect the state of matter?

Increasing temperature can change a solid to a liquid (melting) or a liquid to a gas (evaporation).

What is the difference between a solid, liquid, and gas?

Solids have fixed shapes and volumes; liquids have fixed volumes but take the shape of their container; gases have neither fixed shape nor volume.

How do particles behave in each state of matter?

solids: closely packed, vibrate in place

liquids: close but can flow

gases: far apart, move freely.

What are the common phase changes?

Melting, freezing, condensation, evaporation, sublimation, deposition.