Page 34 - ICC Science Dictionary (spreads)

Word Definition Topic(s) Word Definition Topic(s)

hydrogen Hydrogen bonds are intermolecular B2 ignite Set on fire. C7
bonding attractive forces that develops
between a hydrogen atom and an immune The body's defence system B1a, B1b, B2,
electronegative atom. Hydrogen system against entry of any foreign body, B3
bonding between water molecules including pathogens and agents
involves an attractive force such as pollen grains. The role of
between a hydrogen atom in one the immune system is to prevent
water molecule and the oxygen disease.
atom in another. immunity When a person's body is not prone B3
to a disease because they have
hydrogena- An addition reaction in which C7
tion diatomic hydrogen molecules are a resistance to it, using the cells in
added across carbon to carbon their immune system.
double bonds. immunosup- A type of drug that inhibits a B2

hydroponics A system that involves growing B4 pressant drug patient's immune system and in
plants in a porous material (other doing so prevents it from rejecting
than soil) and allowing water a transplant.
containing nutrients to filter impure A substance that consists of more C8
through it. than one element or compound.

hydroxyl The functional group present in all C7 in vitro In vitro experiments are done in B6
alcohols, -OH. glassware such as test tubes and

hypothalamus The part of the brain that detects B5 Petri dishes.
changes in blood temperature incident ray The incoming ray (of light) with TP2, P6
and water concentration. the arrow pointing towards the

hypothesis A starting point for investigation. An Thinking surface or boundary.
idea or explanation to be tested. scientifically incomplete Burning when there is a limited C7, C9

ice age A time when parts of the Earth's C9 combustion supply of air or oxygen.
surface were covered with large independent Independent variable is the variable Thinking
ice sheets. for which values are changed or scientifically
selected by the investigator.
identify Name or otherwise characterise. Command
word indicator A substance that has different TC3, C4

igneous Formed from magma and lava TC5, B7a, B7b colours, depending upon the pH
cooling down over a long period of the solution it is in.
of time.