Y10 Chemistry Final Exam

Atomic Structure and Bonding

Electrons

Negatively charged subatomic particles

Protons

Positively charged subatomic particles

Neutrons

Neutral subatomic particles found in the nucleus of an atom

Atom

Smallest particles of matter; cannot be further chemically broken down

Element

Contains only ONE kind of atom

Groups/Families

Describes the columns of elements in the period table with similar properties

Period

Describes the rows of the periodic table; indicates the number of electron shells

Metals

These elements are found in the left side and middle of the periodic table

Non-metals

These elements are found in the right side of the periodic table

Noble gases

Group 8 or 18 on the periodic table

Proton number

This number identifies the atom in a periodic table

Atomic Mass number

The total number of neutrons and protons

Alkali metals

The first family of the periodic table

Alkali earth metals

Group II in the periodic table

Compound

Substance made up of atoms of different elements BONDED together

Mixture

Contains difference substances that are NOT bonded together

Molecule

A groups of atoms held together by covalent bonds

Valence

The number electrons on the outermost energy level of an atom

Valency

The number of electrons that each atom needs to gain, lose or share to fill its outer shell

Neutral atom

when the number of protons \= number of electrons

Ion

An atom or group of atoms that has a positive or negative charge.

Ionic compound

A compound that consists of positive (metals) and negative ions (non-metals)

Ionic bond

Formed when one or more electrons are transferred from one atom to another

Bohr Diagram

a diagram that shows the arrangement of an element's subatomic particles and the number of electrons in each shell surrounding the nucleus of an atom

Covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Covalent compound

a chemical compound formed by the sharing of electrons between two non-metals

Metallic bonding

the chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons

Giant molecular structure

substance where large numbers of atoms are joined by covalent bonds forming a strong lattice structure

Diatomic molecule

a molecule that consists of two atoms of the same element (i.e H2)

Allotropes

two or more different molecular forms of the same element (i.e. diamond and graphite)

Giant covalent/molecular structure

A structure with many atoms joined to each other by lots of strong, covalent bonds giving a high melting point and poor electrical conductivity.

Solid covalent/molecular compounds

Atoms are arranged in lattices with weak forces between them; they tend to have low melting points and do not conduct electricity

Solid ionic compounds

Cations and anions arranged in a lattice held together by strong forces; they have high melting points and conduct electricity

Neutralisation reaction

The reaction of an acid and a base forming a salt and water

Single-displacment reaction

chemical reaction in which one element replaces another element in a compound

Combustion reaction

a chemical reaction that occurs when a hydrocarbon reacts with oxygen to produce carbon dioxide and water

Double-displacement reaction

a reaction between two ionic compounds to produce two new compounds (due to the exchange of metallic ions)

Synthesis reaction

a reaction in which two or more substances combine to form a new larger compound

Decomposition

A chemical reaction that breaks down compounds into simpler products.

Catalyst

A substance that speeds up a specific chemical reaction by lowering the activation energy (without being used up in the reaction)

activation energy (Ea)

Energy needed to start a reaction