Chemistry Gateway (OCR)

Atoms

It is the basic building blocks of matter

Protons

Positively charged particles found in the nucleus

Electrons

Negatively charged particles found in orbitals around the nucleus

Neutron

Neutrally charged particles found in the nucleus

Atomic Number

Number of protons in an atom, which defines the element

Mass Number

total number of protons and neutrons in an atom

What is the formula for mass number of atoms?

Mass Number = Number of protons + Number of Neutrons

 Periodic Table

It organizes elements by increasing atomic number and groups elements with similar properties in columns

Element in Group 1 area also known as?

Alkali Metals

Elements in Group 7 are also known as?

Halogens

Periodic Law

It states that elements with similar properties occur at regular intervals when arranged by atomic number

Ionic Bonding

Form when electrons are transferred from one atom to another. This typically happens between metals and nonmetals.

Cation

It is when metal atom loses one or more electron forming positive ion

Anion

It is when nonmetal gains electrons forming negative ion

Covalent Bonding

It is formed when atoms share electrons, typically between nonmetals

Molecules

It is group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction

Metallic Bonding

It occurs between metal atoms, where electrons are shared in a "sea of electrons" that move freely between positive metal ions

Mole

a unit of measurement in chemistry, a small, often dark spot on the skin, a subterranean mammal, or a spy operating within an organization

What is Avogadro’s constant?

Molar Mass

It is a substance is the mass of one mole of its particles (atoms or molecules), typically expressed in grams per mole (g/mol)

What is the formula or Molar Mass?

 Molar Mass = Mass of Substance / Amount of Substance (mol)

Concentration

It is the amount of solute dissolved in a given volume of solution

What is the formula of concentration?

Concentration (mol/dm3) = Amount of Solute (mol)/Volume of Solution (dm3)

What is Acid-Base reaction?

It is when the Acid reacts to Base to produce water and salt, it is also known as neutralizaiton.

What is Oxidation?

It is when the atom losses electrons

What is Reduction?

It is when atom gains electrons

What is Redox Reaction?

Is occurs when the process of oxidation and reduction happened at the same time.

Exothermic reaction

It is when the reaction results in the release of energy usually in the form of heat

Endothermic reaction

It is when the reaction absorbs energy from the surrounding

What is activation energy?

It is the minimum energy required for a reaction to occur. It can be influenced by temperature and catalysts

What is the formula for the Arrhenius equation?

Hydrocarbons

Compounds made up of hydrogen and carbon atoms

Alkanes

Saturated hydrocarbons, e.g., methane (CH₄), ethane (C₂H₆)

Alkenes

Unsaturated hydrocarbons containing double bonds, e.g., ethene (C₂H₄)

Alkynes

Unsaturated hydrocarbons containing triple bonds, e.g., ethyne (C₂H₂)