sec 1 science g3 end of year revision

revise for your end of year exams!

What is science?

Study of the natural world using observation, experiments, and reasoning

What is the scientific method?

Observation → Question → Hypothesis → Experiment → Results → Conclusion

Give the SI unit and instrument for length

Metre (m); ruler or measuring tape

Give the SI unit and instrument for mass

Kilogram (kg); electronic balance

Give the SI unit and instrument for time

Second (s); stopwatch

Give the SI unit and instrument for temperature

Celsius (°C) / Kelvin (K); thermometer

Give the SI unit and instrument for volume

Litre or cubic metre; measuring cylinder

What is accuracy?

Closeness of a measurement to the true value

What is precision?

How consistent repeated measurements are

What is parallax error?

Error caused by reading a scale from the wrong angle

Name the three states of matter

Solid, Liquid, Gas

Describe particle arrangement in solids

Particles are closely packed and vibrate in place

Describe particle arrangement in liquids

Particles are close but can slide past each other

Describe particle arrangement in gases

Particles are far apart and move freely

What is diffusion?

Movement of particles from high concentration to low concentration

What is kinetic particle theory?

All matter is made of tiny particles that are always moving

What happens to particle movement when temperature increases?

Particles move faster

List the changes of state

Melting, Freezing, Evaporation, Boiling, Condensation, Sublimation

Formula for density

Density = Mass ÷ Volume

What is an atom?

Smallest particle of an element that retains its chemical properties

Name the three subatomic particles

Proton (+), Neutron (0), Electron (

Where is each subatomic particle located?

Protons & neutrons → nucleus; Electrons → shells around nucleus

What is atomic number (Z)?

Number of protons in an atom (equals number of electrons in a neutral atom)

What is mass number (A)?

Number of protons + neutrons

How to calculate neutron number?

Neutrons = Mass number

What is a molecule?

Two or more atoms chemically bonded together

Give examples of molecules made of the same element

O₂, N₂, H₂

Give examples of molecules made of different elements

H₂O, CO₂, NH₃

What is a compound?

Two or more elements chemically combined in a fixed ratio

What is a mixture?

Two or more substances physically combined, each retaining its properties

Name three separation techniques

Filtration, Evaporation, Distillation

What is the basic unit of life?

Cell

List the differences between plant and animal cells

Plant

What is the order of biological organization?

Cell → Tissue → Organ → System → Organism

Name the major human body systems

Digestive, Circulatory, Respiratory, Excretory, Muscular & Skeletal, Nervous

What is energy?

Ability to do work

List forms of energy

Kinetic, Potential, Heat, Light, Electrical, Chemical, Sound

What is the law of conservation of energy?

Energy cannot be created or destroyed, only changed from one form to another

What is force?

A push or pull that can change motion, speed, direction, or shape

Name types of forces

Gravity, Friction, Magnetic, Elastic

Difference between balanced and unbalanced forces

Balanced → no change in motion; Unbalanced → causes movement

How does light travel?

In straight lines

What is reflection?

Bouncing of light off a surface

What is refraction?

Bending of light when passing from one medium to another

Define opaque, transparent, and translucent

Opaque

How does heat flow?

From hot objects to cold objects

Name the three methods of heat transfer

Conduction (solids), Convection (fluids), Radiation (waves)

Formula for weight

Weight = Mass × Gravity