Introduction to Atomic Structure and Chemical Reactions

Vocabulary practice flashcards covering atomic structure, subatomic particles, isotopes, ions, matter classification, chemical reactions, the pH scale, and balancing chemical equations based on the lecture transcript.

Atom

The smallest particle of an element that keeps its chemical properties.

Subatomic particles

The three components of an atom: protons, neutrons, and electrons.

Proton

A subatomic particle with a charge of $+1$ found in the nucleus that determines the identity of the element.

Neutron

A subatomic particle with a charge of $0$ found in the nucleus.

Electron

A subatomic particle with a charge of $-1$ and almost no mass, located in electron shells around the nucleus.

Nucleus

The dense centre of an atom containing protons and neutrons.

Atomic number

The total number of protons in the nucleus of an atom.

Mass number

The total number of protons and neutrons in an atom ($\text{Protons} + \text{Neutrons}$).

Neutron Formula

$\text{Mass number} - \text{Atomic number}$.

Isotope

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

Ion

A charged atom formed when electrons are gained or lost.

Cation

A positive ion formed when an atom loses electrons.

Anion

A negative ion formed when an atom gains electrons.

Element

A pure substance made of only one type of atom.

Compound

A substance made of two or more elements chemically bonded together, such as Water ($H_2O$).

Mixture

Two or more substances physically mixed together that can be separated physically, such as Air.

Chemical reaction

A process where atoms rearrange to form new substances; atoms are neither created nor destroyed.

Reactants

The starting substances in a chemical reaction.

Products

The new substances formed as a result of a chemical reaction.

Chemical equation

A symbolic way of showing a chemical reaction; it must be balanced to show the same number of atoms on both sides.

Law of Conservation of Mass

The law stating that mass is neither created nor destroyed during a chemical reaction.

Combustion

A reaction where $\text{fuel} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water}$.

Neutralisation

The reaction between an acid and a base to produce $\text{salt} + \text{water}$.

Acid + Metal reaction

A reaction that produces $\text{salt} + \text{hydrogen}$.

Acid + Carbonate reaction

A reaction that produces $\text{salt} + \text{water} + \text{carbon dioxide}$.

pH Scale

A scale where acids are less than $7$, bases are greater than $7$, and neutral substances are exactly $7$.

Hydrochloric acid

An example of a strong acid.

Vinegar

An example of a weak acid.

Sodium hydroxide

An example of a base.

Litmus paper

An indicator that turns red in acid and blue in base.

Universal indicator

An indicator that turns green at pH $7$.

Periodic table

A table of all known elements arranged so that elements in the same group have similar properties and elements in the same period have the same number of electron shells.

Metals

Elements that are usually good conductors of heat and electricity.

Non-metals

Elements that are usually poor conductors of heat and electricity.

Physical change

A change in which no new substance is formed.

Chemical change

A change in which a new substance is formed.

Signs of a chemical reaction

Indicators including colour change, gas production, temperature change, light production, precipitate formation, or odour changes.

Balanced equation: Hydrogen and Oxygen

$$2H_2 + O_2 \rightarrow 2H_2O$$

Balanced equation: Magnesium and Oxygen

$$2Mg + O_2 \rightarrow 2MgO$$

Balanced equation: Iron and Oxygen

$$4Fe + 3O_2 \rightarrow 2Fe_2O_3$$

Balanced equation: Sodium and Chlorine

$$2Na + Cl_2 \rightarrow 2NaCl$$

Balanced equation: Methane and Oxygen

$$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$$