Year 10 Chemistry Test Term 3 Flashcards Preview

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Flashcards in Year 10 Chemistry Test Term 3 Deck (16):

Define: Atom

The smallest article of an element that cannot be split into smaller particles by chemical means. In the centre is a nucleus containing neutrons and protons, orbiting are electrons.


Define: Element

A substance composed of atoms with the same atomic number.


Define: Molecule

Two or more atoms held together by covalent bonds.


Define: Compound

Compounds are formed from two or more different elements which are chemically combined, either ionically, covalently or both.
e.g. NaCl


Define: Mixture

A substance made up of different elements or compounds mixed together but not chemically joined.
e.g. Soil, Air, Salt Water


Define: Isotopes

Atoms that have the same number of protons but a different number of neutrons.


Explain Electron Configuration

Electron configuration is the amount of electrons surrounding the nucleus, which are arranged in shells.
e.g. Chlorine electronic configuration: 2,8,7


Define: Anion

Negatively Charged Ion Atom, occurring when an atom gains an electron.


Define: Cation

Positively Charged Ion, occurring when an atom loses an Electron.


What is the outer shell of electrons called?

Valence Electrons


What do Valence Electrons tell us about the atom?

The amount of Valence Electrons determines how reactive an atom is.


What does the Atomic Number represent?

The number of protons within an atom


What does atomic weight represent?

Average weight of the atom, measured in atomic mass units.


Which elements are most reactive? Why?

Elements with a nearly empty or nearly full Valence shell. This is because they are either trying to lose an electron or gain an electron to become stable.


What is the Octet Rule?

That all elements are trying to have 8 Electrons on its outermost shell (Valence) shell, by gaining or losing Electrons to become stable.


Explain Ionisation Energy

The energy needed to remove electrons from an atom. Large atoms require low ionisation energy, while small atoms require high ionisation energy.