SCI REV

Question 1

In atomic structure, what does an element’s atomic number equal?

Answer 1

Number of protons.

Question 2

Atomic structure: what does the mass number represent?

Answer 2

Total protons + neutrons.

Question 3

Atomic structure: what defines isotopes of the same element?

Answer 3

Same protons, different neutrons.

Question 4

Atomic structure: in a neutral atom, how do electrons compare to protons?

Answer 4

Electrons equal protons.

Question 5

Electron configuration (first 20): what is the shell filling pattern?

Answer 5

2, 8, 8, 2.

Question 6

Electron configuration: what does the highest occupied shell indicate?

Answer 6

The element’s period.

Question 7

Periodic trends: what do elements in the same group share?

Answer 7

Same number of valence electrons.

Question 8

Periodic trends: how does atomic radius change across a period?

Answer 8

Decreases due to increasing nuclear charge.

Question 9

Periodic trends: how does atomic radius change down a group?

Answer 9

Increases due to added shells and shielding.

Question 10

Periodic trends: how does first ionisation energy change across a period?

Answer 10

Generally increases (harder to remove electrons).

Question 11

Periodic trends: how does first ionisation energy change down a group?

Answer 11

Decreases (more shielding, electrons further out).

Question 12

Periodic table: which groups are most reactive metals?

Answer 12

Group 1 alkali metals (down the group reactivity increases).

Question 13

Periodic table: which group contains very reactive non-metals?

Answer 13

Group 17 halogens (reactivity generally decreases down the group).

Question 14

Periodic table: what characterises noble gases (Group 18)?

Answer 14

Full valence shells; very unreactive.

Question 15

Bonding: what happens in ionic bonding at the electron level?

Answer 15

Electrons transfer from metal to non-metal.

Question 16

Bonding: what holds an ionic lattice together?

Answer 16

Electrostatic attraction between cations and anions.

Question 17

Ionic compounds: when do they conduct electricity?

Answer 17

When molten or dissolved (mobile ions).

Question 18

Bonding: what happens in covalent bonding?

Answer 18

Non-metals share electron pairs.

Question 19

Covalent substances: how do simple molecules typically behave electrically?

Answer 19

Poor conductors (no mobile charges).

Question 20

Metallic bonding: why are metals good conductors?

Answer 20

Mobile delocalised electrons carry charge/heat.

Question 21

Naming: how do you name simple ionic compounds?

Answer 21

Cation name first, then anion with “-ide” (e.g., sodium chloride).

Question 22

Formulas: what ionic charges do Group 1, 2, 17 typically form?

Answer 22

+1, +2, and −1 respectively.

Question 23

Polyatomic ions: give the formula and charge of sulfate.

Answer 23

SO₄²⁻ (sulfate carries −2).

Question 24

Reactions: what are the products of acid + metal?

Answer 24

Salt + hydrogen gas.

Question 25

Reactions: what are the products of acid + carbonate?

Answer 25

Salt + CO₂ + water.

Question 26

Reactions: what are the products of neutralisation (acid + base)?

Answer 26

Salt + water.

Question 27

Reaction types: define decomposition reaction.

Answer 27

One reactant breaks into simpler products.

Question 28

Reaction types: define Composition reaction.

Answer 28

Two or more reactants form one product.

Question 29

Reaction types: define precipitation reaction.

Answer 29

Two solutions form an insoluble solid (precipitate).

Question 30

Conservation of mass: what must balance in a chemical equation?

Answer 30

Number of atoms of each element.

Question 31

Light physics: define reflection law at a plane surface.

Answer 31

Angle of incidence equals angle of reflection.

Question 32

Light physics: what is refraction?

Answer 32

Bending of light when it changes medium (speed changes).

Question 33

Refraction: how does light bend entering a denser medium?

Answer 33

Toward the normal (speed decreases).

Question 34

Optics: what is the refractive index conceptually?

Answer 34

A measure of how much a medium slows light.

Question 35

Color/EM: what is the visible light wavelength range?

Answer 35

~700 nm (red) to ~400 nm (violet).

Question 36

EM spectrum: place radio, microwave, infrared in order of frequency.

Answer 36

Radio < Microwave < Infrared.

Question 37

EM uses: what common uses do microwaves have?

Answer 37

Microwave ovens and Wi-Fi communications.

Question 38

Sound: in which medium is sound fastest—gas, liquid, or solid?

Answer 38

Fastest in solids, slowest in gases.

Question 39

Waves: define amplitude.

Answer 39

Height of the wave measured from the rest position to the crest or trough in m.

Question 40

Waves: state the wave equation.

Answer 40

v = f × λ. Velocity = Wavelength x Frequency

Question 41

Kinematics: what does the slope of a distance–time graph represent?

Answer 41

Speed/velocity (if direction considered).

Question 42

Kinematics: what does the slope of a velocity–time graph represent?

Answer 42

Acceleration.

Question 43

Kinematics: what does area under a velocity–time graph represent?

Answer 43

Displacement.

Question 44

Motion: state Newton’s First Law (inertia).

Answer 44

A body remains at rest or uniform motion unless acted on by net force.

Question 45

Motion: write Newton’s Second Law.

Answer 45

F = m × a.

Question 46

Motion: state Newton’s Third Law.

Answer 46

Every action has an equal and opposite reaction.

Question 47

Forces: what is weight and its equation?

Answer 47

Gravitational force: W = m × g.

Question 48

Energy: give kinetic energy formula and meaning.

Answer 48

KE = ½mv² (energy of motion).

Question 49

Energy: give gravitational potential energy formula.

Answer 49

GPE = mgh.

Question 50

Energy: define work and its equation.

Answer 50

Energy transfer by force over distance: W = F × d (parallel).

Question 51

Energy: what is power and its equation?

Answer 51

Rate of energy transfer: P = ΔE/Δt (or P = Fv).

Question 52

Efficiency: how is efficiency calculated?

Answer 52

Useful output ÷ total input (×100%).

Question 53

Genetics: define gene vs chromosome.

Answer 53

Gene: DNA segment coding for protein; Chromosome: packaged DNA.

Question 54

Genetics: what is a karyotype used for?

Answer 54

Displaying chromosome set to identify sex or abnormalities.

Question 55

DNA: what does “triplet/codon” specify?

Answer 55

Three bases code one amino acid.

Question 56

Mutations: define point mutation.

Answer 56

Single-nucleotide change (substitution/insertion/deletion).

Question 57

Mutations: define frameshift mutation.

Answer 57

Insertion/deletion altering the reading frame.

Question 58

Meiosis: what is produced and why it matters?

Answer 58

Four genetically unique haploid gametes (genetic variation).

Question 59

Inheritance: what do offspring receive from each parent?

Answer 59

One allele of each gene.

Question 60

Pedigrees: what pattern suggests an autosomal recessive trait?

Answer 60

Can skip generations; affected often from unaffected carriers.

Question 61

Monohybrid crosses: expected phenotype ratio for Aa × Aa?

Answer 61

3:1 dominant:recessive.

Question 62

Periodic reactivity: why do alkali metals get more reactive down the group?

Answer 62

Outer electron further from nucleus; easier to remove.

Question 63

Halogen reactivity: why does it generally decrease down Group 17?

Answer 63

Larger atoms gain electrons less readily (more shielding).

Question 64

Ionic vs covalent: which typically has higher melting point and why?

Answer 64

Ionic solids; strong lattice electrostatic forces.

Question 65

Acids: what ion do acids produce in water, and bases?

Answer 65

Acids: H⁺ (or H₃O⁺); Bases: OH⁻.

Question 66

Indicators: what does universal indicator show for neutralisation endpoint?

Answer 66

pH approaches 7 (green).

Question 67

Reaction rates: name two factors increasing rate.

Answer 67

Higher temperature, greater surface area (also concentration, catalysts).

Question 68

Light: what causes dispersion in a prism?

Answer 68

Wavelength-dependent refraction (different speeds in medium).

Question 69

Waves: difference between transverse and longitudinal waves?

Answer 69

Transverse oscillate perpendicular; longitudinal parallel to direction.

Question 70

Motion graphs: how identify constant acceleration on v–t graph?

Answer 70

Straight line with non-zero slope.

Question 71

Work–energy: what does net work equal for a particle?

Answer 71

Change in kinetic energy (Work–Energy Theorem).

Question 72

Genetics: what is crossing over and when does it occur?

Answer 72

Homologous exchange in prophase I; increases variation.

Question 73

Genetics: define independent assortment.

Answer 73

Random alignment of homologs in metaphase I creates new combinations.

Question 74

EM hazards/benefits: one benefit and one risk of UV?

Answer 74

Sterilisation/Vitamin D; sunburn/DNA damage.

Question 75

Sound: what property controls perceived pitch?

Answer 75

Frequency.

Question 76

Sound: what property controls perceived loudness?

Answer 76

Amplitude (sound pressure).

Question 77

Electricity (basics): what is current vs voltage?

Answer 77

Current: charge flow; Voltage: energy per charge (potential difference).

Question 78

Circuits: how does resistance combine in series vs parallel?

Answer 78

Series: add; Parallel: reciprocals add (1/Rₜ = 1/R₁ + …).

Question 79

Data skills: what does a steep slope on distance–time imply?

Answer 79

Higher speed.