KS3 YEAR 9 SCIENCE FLASHCARDS (copy)

What are the three states of matter?

Solids, liquids, gases

What is a property?

A description of how a material behaves or what it looks like.

Give two properties of solids

They don't flow, they can't be compressed

Give two properties of liquids

Can flow, cannot be compressed

Give two properties of gases

Can flow, can be compressed

Describe the arrangement of particles in a solid.

Regular arrangement, particles are touching

Describe the arrangement of particles in a liquid.

Irregular arrangement, particles are touching

Describe the arrangement of particles in a gas.

Irregular arrangement, particles are not touching

What holds the particles in a solid together?

Strong forces of attraction

What holds the particles in a liquid together?

Medium strength forces of attraction

How do the particles in a solid move?

They vibrate on the spot

What is the name for the process of solids turning to liquids?

Melting

What is the name for the process of liquids turning to solids?

Freezing

What is the melting point of a substance?

The temperature at which it melts

What is the name for the process of liquids turning to gases?

Boiling (or evaporation)

What is the name for the process of gases turning to liquids?

Condensing

What is the boiling point of a substance?

The temperature at which it boils

What types of substances melt at a specific temperature?

Pure substances

What type of substances melt over a range of temperatures?

Mixtures

When salt is added to water and stirred, what happens?

The salt dissolves

When a solid dissolves in a liquid, what is formed?

A solution

What do we call the solid that dissolves in a liquid?

Solute

What do we call the liquid that a solid dissolves into?

Solvent

What is an insoluble solid?

A solid that will not dissolve in a solvent

What is a soluble solid?

A solid that will dissolve in a solvent

What is the effect of increasing the temperature on solubility?

The greater the temperature, the greater the solubility

What word do we use to describe how easily a solute dissolves?

Solubility

What is a saturated solution?

One in which no more solute can dissolve

How do we separate an insoluble solid mixed with a liquid?

Filtration

What is the liquid left in the conical flask after filtrations called?

The filtrate

What is the solid left in the filter paper after filtration called?

The residue

What equipment is needed for filtration?

Filter paper, funnel, conical flask

How do we separate a soluble solid from a liquid?

Evaporation

How do we separate two liquids that are mixed together?

Distillation

How do we separate the dyes in ink?

Chromatography

What is an organism?

A living thing

What is a cell?

The building block of all organisms

What is an organelle?

A small part of a cell

Give the name of the organelle that holds the DNA and controls the cells activities.

Nucleus

Give the name of the layer around the cell that controls what enters or leaves the cell

Cell membrane

Give the name of the gel like substance where most chemical reactions take place in a cell.

Cytoplasm

Give the name of the small organelle that performs respiration

Mitochondria

For what purpose do cells perform respiration?

To provide the cell with energy

Give the name of the rigid layer that strengthens a cell and supports its shape

Cell wall

Give the name of the small organelle that performs photosynthesis

Chloroplast

Name the three organelles that are found in plant cell, but not animal cells

Cell wall, chloroplasts, vacuole

Name five organelles that are present in both animal and plant cells

Nucleus, mitochondria, ribosomes, cytoplasm, cell membrane

What do we use to look at things too small for the naked eye?

A microscope

What are the three main steps needed for looking at something through a microscope?

1. Start with the lowest magnification objective lens. 2. Focus using the focus wheels. 3. Increase the magnification (if you need to)

What happens when we focus a microscope?

The image becomes sharp enough to see (clearer)

What does magnification mean?

Making something look bigger

What word do we use to describe how big something really is?

Actual size

What word do we use to describe how big something looks through a microscope?

Image size

What equation do we use to work out image size?

Image size = magnification x actual size

What is a specialised cell?

A cell which has a specific function (job)

Name two specialised animal cells

Red blood cell, muscle cell, sperm cell

What is the function of the red blood cell?

Carry oxygen round the body

Give two adaptations of the red blood cell

No nucleus, biconcave shape

Why does a red blood cell have no nucleus?

More space for oxygen

Why does a red blood cell have a biconcave shape?

Easier to move through blood vessels

What is the function of the muscle cell?

To contract and move things (e.g. bones

Give one adaptation of a muscle cell?

Lots of mitochondria

Why do muscle cells have lots of mitochondria?

To release energy for movement

Give two examples of specialised cells in plants

Root hair cell, palisade cell

What is the function of a root hair cell?

Absorb water (and nutrients) from the soil

Give two ways in which a root hair cell is specialised to its function

Large extension, no chloroplast

Why do root hair cells have large extensions?

To increase their surface area

Why do root hair cells not have any chloroplasts?

There is no light underground so there is no photosynthesis

What is an area of high concentration?

Where there are lots of particles

What is an area of low concentration?

Where there are few particles

What is diffusion?

The movement of particles from an area of high concentration to an area of low concentration

In cells, what three factors affect diffusion?

Concentration gradient, temperature, cell surface area

What word do we use for the size of the difference in concentration between two places?

Concentration gradient

How does concentration gradient affect rate of diffusion?

The greater the concentration gradient, the greater the rate of diffusion

How does temperature affect the rate of diffusion?

The greater the temperature, the greater the rate of diffusion

How does cell surface area affect the rate of diffusion?

The greater the cell surface area, the greater the rate of diffusion

What three things can a forces do to an object?

Change an objects speed, shape or direction

What is the name of the force produced when solid surfaces rub against each other?

Friction

What is the name of the force produced by engines?

Thrust

What is the name of the force produced when an object moves through the air?

Air resistance

What is the name of the force produced when an object moves through water?

Water resistance

What is the name of the force that stops objects sinking on water?

Upthrust

What is the name of the force that pulls objects towards Earth?

Weight

What is the name of the force that stops objects falling through solid surfaces?

Normal reaction force

What is the name of the force that causes metals to be attracted or repelled by magnets?

The magnetic force

What is the name of the force that causes charges to be attracted or repelled?

The electrostatic force

What is the name of the force that stops airplanes falling down through the air?

Lift

What is a contact force?

A force which requires objects to be touching

Give 3 examples of a contact force

friction, thrust, air resistance, water resistance, upthrust

What is a non-contact force?

A force which does not require objects to be touching

Given an example of a non-contact force

Weight, magnetic

What are forces measured in?

Newtons (N)

What do we use to measure forces?

Newton meters

What is a resultant force?

The overall force when several forces combine

What is extension?

Increasing the length of an object

What is compression?

Decreasing the length of an object

What is Hooke’s law?

As the force on a spring increases so does the extension

Name the five main energy stores

Thermal, kinetic, gravitational, chemical, elastic

Which energy store is involved in changes in temperature?

Thermal

Which energy store is involved in movement?

Kinetic