7SC2023 Examination

Examination Practise

Identify a way that water ca re-enter the atmosphere:

Evaporation

Pure Substances (atom)

Cannot be Separated

Pure Substances (compound)

Can be destroyed

Composed of 2 or more different atoms bonded.

Mixture

Substance made by mixing other substances together

Solution

Mixture of solute dissolved into a solvent

Examples: Sugar & Coffee

Suspension

Mixture of gas / liquid

Insoluble Substance

Examples: Chalk & Water

Colloid

Mixture in which the particles of 1 substance spread evenly throughout another

Example: Milk

Emulsion

Dispersed in other

Example: Oil

Homogenous

Mixture in which the composition is uniform throughout the mixture

(salt water)

Heterogenous

Mixture in which the composition is uniform throughout the mixture

(soup)

Solution

Mixture of a solute dissolved into a solvent

Solvent

Substance in which a solute dissolves to form a solution

Solute

Substance that is dissolved into a solvent to form a solution

Insoluble

Collects at the bottom of the container are sediments

Soluble

Dissolvable

Dilute

Describes a solution to make it weaker by adding solvent

Saturated

Containing the maximum amount of solute

Concentrated

Amount of solute compared to the amount of solvent in a solution

Evaporation / Crystallisation

A separation technique that uses evaporation to separate the parts of a solution

Distillation

A separation technique that uses evaporation to separate substances

Decanting

A technique separating off the liquid part of a suspension, leaving the solid sediment behind

Filtration

The part of the mixture that passes through a filter

Sieving

A method to distinguish small particles from bigger particles

Centrifuging

Separates heterogeneous mixtures into their various components

(liquids to liquids)

(solids to liquids)

(liquids to gas)

Separation Funnel

Used in liquid-liquid extractions to separate the compositions of a mixture into 2 immiscible solvent phases of different densities

(Reading Elements from the Periodic Table)

Atomic Number

The number of protons in the nucleus of an atom.

(Reading Elements from the Periodic Table)

Mass Number

The total number of protons & neutrons in the nucleus.

(Reading Elements from the Periodic Table)

Atomic Symbol

The number of protons in the nucleus of the atom.

Periods in the Periodic Table

Each period represents a new shell

Groups in the Periodic Table

Each group represents outer electrons.

Protons in the Atomic Structure

Positive Charge

Neutrons in the Atomic Structure

Neutral / No change

Electrons in the Atomic Structure

Negative charge

Shells in the Atomic Structure

Amount of electrons that uses space

Nucleus in the Atomic Structure

Cell’s control centre

Density

The substances mass per unit of volume

This Symbol Represents?

Radiation

This Symbol Represents?

High Voltage

This Symbol Represents?

Oxidiser

This Symbol Represents?

Harmful

This Symbol Represents?

Corrosive, irritant effect on skin

This Symbol Represents?

Flammable

This Symbol Represents?

Toxic

This Symbol Represents?

Explosive

Biology

Study of living things

Chemistry

Study of substances

Physics

Study of Energy

Earth Science

Study of processes on earth

Space Science

Study of space

Clarify what science equipment is this?

Thermometer

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Micro-Scope

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Beaker

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Bunsen Burner

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Tripod

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Test Tube

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Rhetort Stand

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Clonical Flask

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Filter Funnel

Independent Variable

One single variable that is changed in science

A force is a

“push”

“pull”

“twist”

A force can:

1.        Change an object’s shape.

2.       Speed an object up (accelerate)

3.        Stop an object moving.

4.       Slow an object down.

5.     Change an object’s direction.

UNITS OF FORCES:

Always measured in Newtons

Definition of WORK

In science, 'work' is 'motion' caused by a force.

Equation for Work

Work (W) = Force (F) x distance (d)

Work is measured in

Joules

Force is measured in

Newtons

Distance is measured in

Metres

Vector Diagrams

“We represent forces using…

Arrows

Define a Balanced Force

The left force and the right force is 50 N (Newtons)

Define an unBalanced Force

The left force is greater than the right force

THE RAMP

How do they make life easier? When using a ramp, the load force remains the same but the effort force is… (Increased OR Decreased)

Decreased, as less effort Is required, thus requiring a larger distance

Definition of Weight

• Weight: the gravitational force on an object

• Measured in Newtons.

Definition of Mass

• Mass: how much matter on object contains

• Measured in kilograms.

Gravity’s influence:

Mass always stays the same, but weight can change depending on how much gravity is acting upon an object.

Definition of friction:

The resistance that one surface or object encounters when moving over another.

Factors contribution to high friction:

Rough Surfaces

Factors contribution to low friction:

Whiteboard

Buoyancy

Definition:

Buoyancy is an upward force exerted by a fluid that opposes the weight of an submerged object.

Displacement:

Definition:

:  is how much water it is pushing away

Density:

Definition

Objects that are more dense than water will sink

NEWTONS 1ST LAW OF MOTION

INERTIA: Objects resistance to change.

An object in motion will continue moving

An object at rest will remain at rest.

Which categories are prey:

1. Tertiary Consumers

2. Secondary Consumers

Which categories are predators:

1. Secondary Consumers

2. Primary Consumers

Definition of a Biotic Factor

A living thing, as an animal or plant, that influences or affects an ecosystem:

Definition of an Abiotic Factor

A nonliving condition or thing, as climate or habitat, that influences or affects an ecosystem and the organisms in it:

KEYTERMS:

Ecology

Study of the environment

KEYTERMS:

Biosphere

Global ecosystem composed of living organisms

KEYTERMS:

Community (INTERACTIONS BETWEEN ORGANISMS)

Diverse group of organisms that interact in a common location

KEYTERMS:

Population (INTERACTIONS BETWEEN ORGANISMS)

Group of individually of the same species living and interbreeding within a given area

Ecosystem

(BUBBLE OF LIFE) Consists of plants, animals and other organisms.

Usually ordered in categories using
Food Chains / Food Webs

Habitat

Natural home for an animal / creature

Dichotomous Key

Important scientific tool, used to identify different organisms

Energy Pyramid

Graphical Representation of the energy found within the tripod levels of an ecosystem

Deforestation

• Loss of trees

• Habitat Destruction

Food Chain

Consists of Producers, Consumers, etc…

Food Web

Consists of multiple food chains in 1 graphical representation

Producer

The beginning stage of a food web

Energy is received from the sun

Consumer

An organism that cannot produce its own food

Herbivore

Plant - eaters

Carnivore

Meat - eaters