Year 9 IGCSE Chemistry

Atomic Structure

• The smallest unit of matter that still retains the properties of an element is an atom.

Ion Formation

• Atoms gain or lose electrons to form ions through a process called ionization.

Chemical Bonding

• Covalent bonds are characterized by the sharing of electrons between atoms.
• The attraction between two atoms that share a pair of electrons is known as a covalent bond.
• The term for the attraction between two atoms that share a pair of electrons is also referred to as electron pair bond.

Energy and Electrons

• The energy required to remove an electron from an atom in its ground state is known as ionization energy.

Atomic Structure

• The smallest unit of matter that still retains the properties of an element is an atom.

Ion Formation

• Atoms gain or lose electrons to form ions through a process called ionization.

Chemical Bonding

• Covalent bonds are characterized by the sharing of electrons between atoms.
• Electrons shared between atoms form a chemical bond, with the attraction between the atoms being called a covalent bond.
• Ionic bonds, on the other hand, are formed through the transfer of electrons between atoms.

Energy and Electrons

• The energy required to remove an electron from an atom in its ground state is called ionization energy.
• The energy change associated with the formation of a covalent bond is called bond energy.

Atoms vs. Molecules

• The main difference between an atom and a molecule is that an atom is a single unit of an element, while a molecule is a group of two or more atoms bonded together.

Electron Arrangement

• When an atom gains or loses electrons, its electron arrangement changes, resulting in the formation of ions.

Electron Properties

• One true statement about electrons is that they are involved in chemical bonding through sharing or transfer.