Page 45 - ICC Science Dictionary (spreads)

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

nuclear fuels Radioactive materials, usually P1, P4 nucleus The central part of an atom. It C1, P4
uranium or plutonium, used in contains protons and neutrons, and
nuclear reactors. has most of the mass of the atom.
nuclear The joining together of two smaller P4, P8 The plural of nucleus is nuclei.
fusion atomic nuclei to produce a larger obesity The medical term for being very B2, B5
nucleus. Radiation is released overweight, owing to the excessive
when this happens. Nuclear fusion accumulation of body fat.
happens in stars like our Sun, and objective In a compound microscope, the B1a, B1b
in hydrogen bombs. lens lens closest to the specimen has
nuclear The scientific idea that an atom has C1 a very short focal length and
model electrons surrounding a nucleus produces a greatly magnified
that contains protons and neutrons. image of the specimen.
nuclear Particles or waves given out by P4 oestrogen A female sex hormone produced B5
radiation the nucleus of an unstable atom. in the ovaries, which is responsible
Alpha particles, beta particles and for puberty in girls and the
gamma waves are the three most regulation of the menstrual cycle.
common types of nuclear radiation. ohmic A device that obeys Ohm's Law - P2

nuclear Changes that occur in the nucleus P4 conductor potential difference and current
reaction of an atom. Eg due to radioactive are proportional, eg wire, resistor.
decay, nuclear fission or nuclear Ohms Unit of measuring a components TP3
fusion. resistance
nuclear A piece of equipment in which P4 Ohm’s Law The rule that states that the TP3, P2
reactor nuclear fission or fusion takes place. current (I) flowing through a
nuclei The nucleus controls what B2, P4, P8 resistor (R) is directly proportional
happens inside the cell. to the voltage (V) across the
Chromosomes are structures resistor, provided the temperature
found in the nucleus of most cells. remains constant.
The plural of nucleus is nuclei. omnivore An animal that eats both plants B7a, B7b

nucleotide The units or molecules of which B6, C7 and animals.
DNA or RNA is composed onion skin Rock is heated by the sun and TC5

nucleus Contains genetic material (DNA) TB1, B1a, B1b, cools at night. This causes the rock
which controls the cell’s activities. B2, B3, B6 to expand and contract, leading
to layers of rock ‘peeling away’.