Chemistry – Bonding and Reaction Types (finish deck and still read notes to understand periodic table trends)

Question 1

Atoms: structure, molecular mass

Answer 1

Structure: Atoms consist of a nucleus (containing protons and neutrons) surrounded by electrons in shells.
Molecular Mass: The sum of the atomic masses of all atoms in a molecule.

Question 2

Identify how many protons, neutrons and electrons an atom has based on its atomic number and relative atomic mass.

Answer 2

Atomic Number (Z): Number of protons; equals the number of electrons in a neutral atom.
Relative Atomic Mass (A): Mass number = protons + neutrons.
Neutrons: Neutrons = A - Z

Question 3

Atomic number

Answer 3

The number of protons in an atom’s nucleus, unique to each element.

Question 4

Mass Number

Answer 4

The total number of protons and neutrons in an atom’s nucleus.

Question 5

relative atomic mass of an atom

Answer 5

The weighted average mass of an element’s isotopes, compared to carbon-12.

Question 6

Common properties of elements (alkali metals, alkaline earth metals, halogen and noble gas) (study further)

Answer 6

Alkali metals (Group 1): Highly reactive, soft, low melting points, form +1 ions.
Alkaline earth metals (Group 2): Less reactive, harder, higher melting points, form +2 ions.
Halogens (Group 17): Reactive non-metals, form -1 ions, exist as diatomic molecules.
Noble gases (Group 18): Inert, with full outer electron shells, unreactive.

Question 7

Metals, non-metals and metalloids

Answer 7

Metals: Shiny, conductive, malleable, high melting and boiling points lose electrons to form cations.
Non-metals: Poor conductors, brittle, low melting and boiling points, gain electrons or share them in reactions.
Metalloids: Properties between metals and non-metals, semiconductors.

Question 8

Electron configuration using the Bohr model

Structure of atoms in terms of electron shells

Energy of electrons to shells

Movement of electrons

Answer 8

Bohr Model: Electrons orbit the nucleus in fixed paths (energy levels).
Electron Shells: Shell 1 can hold 2, shell 2 can hold 8, shell 3 can hold 18, etc. (check these levels to see if right with old test)

Question 9

Know the difference between ions, molecules and compounds

Answer 9

Ions: Charged atoms (cations = positive, anions = negative).
Molecules: Two or more atoms bonded together (can be the same or different).
Compounds: Pure substances made from two or more different elements.

Question 10

Covalent Bond

Answer 10

A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. Covalent bonding generally happens between nonmetals

Question 10

Features/properties of ionic compounds, metals, covalent molecules

Answer 10

Ionic Compounds: High melting points, soluble in water, conduct electricity in solution.
Metals: Conductive, malleable, ductile.
Covalent Molecules: Lower melting points, can be gases or liquids.

Question 11

Bonding: Putting together ionic compounds and covalent molecules (Covalent vs Ionic bonding)

Answer 11

Ionic Bonding: Transfer of electrons from one atom to another. Ionic bonds occur between metals, losing electrons, and nonmetals, gaining electrons.
Covalent Bonding: Sharing of electrons between non-metals

Question 12

Identify a covalent bonded molecule by the presence of two non-metals bonded together via the sharing of electrons

Answer 12

Covalent Molecule: Formed by two non-metals sharing electrons.

Question 13

Identify if a molecule contains single, double or triple bonds

Answer 13

Single Bond: One pair of shared electrons.
Double Bond: Two pairs of shared electrons.
Triple Bond: Three pairs of shared electrons.

Question 14

Draw Lewis Dot Diagrams (electron dot diagrams)

Answer 14

Show valence electrons as dots around the element symbol.

Question 15

Valency of an element (electrons it needs to gain, lose or share)

Answer 15

Valency: The number of electrons an element needs to gain, lose, or share to achieve stability.

Question 16

Formula of simple covalent and ionic compounds (from valency of their constituent element)

Answer 16

Covalent Compounds: Combine based on shared electrons.
Ionic Compounds: Combine based on charges (balance the total charge).

Question 17

Know the difference between reactants and products and understand the concept of ‘Conservation of mass’

Answer 17

Reactants: Substances that undergo a chemical change.
Products: Substances formed from the reaction.
Conservation of Mass: Mass of reactants equals mass of products.

Question 18

Identify the signs of a chemical change

Answer 18

Color change, gas production, precipitate formation, temperature change.

Question 19

Writing worded equations and balanced chemical equations

Answer 19

Worded Equations: Describe reactants and products in words.
Balanced Equations: Show equal numbers of each type of atom on both sides, with states.

Question 20

Balancing chemical equations and writing states

Answer 20

Adjust coefficients to ensure the same number of atoms on each side.

Question 21

Predict if a precipitation reaction will occur using solubility rules and identify the precipitate formed

Answer 21

Check solubility rules: If one of the products is insoluble in water, it forms a precipitate.
Identify the precipitate: The insoluble compound that forms a solid in the reaction.
Example: AgNO₃ + NaCl → AgCl (precipitate) + NaNO₃ (soluble).

Question 22

Write worded and balanced chemical equations involving single and double displacement reactions, decomposition, combination, combustion, and neutralisation reactions.

Answer 22

Single Displacement: A + BC → AC + B
Double Displacement: AB + CD → AD + CB
Decomposition: AB → A + B
Combination: A + B → AB
Combustion: Hydrocarbon + O₂ → CO₂ + H₂O
Neutralization: Acid + Base → Salt + Water

Question 23

Use the acid anion and base cation to determine the salt produced in a neutralisation reaction

Answer 23

Acid anion: Negative ion from the acid (e.g., Cl⁻ from HCl).
Base cation: Positive ion from the base (e.g., Na⁺ from NaOH).
To find the salt, combine the acid anion and base cation:

Example: HCl + NaOH → NaCl (salt) + H₂O.

Question 24

Identify exothermic and endothermic reactions based on temperature change

Answer 24

Exothermic: Release heat (temp increase).
Endothermic: Absorb heat (temp decrease).