Questions with Correct Detailed Answers latest
2025 Version
matter - Answer Anything that takes up space and has mass.
element - Answer Any substance that cannot be broken down to any other substance by chemical
reactions.
compound - Answer A substance consisting of two or more different elements combined in a fixed ratio.
emergent properties - Answer Properties not possessed by the constituents.
What four elements make up 96% of living matter? - Answer carbon, hydrogen, oxygen, nitrogen
essential element - Answer A chemical element required for an organism to survive, grow, and
reproduce.
trace element - Answer An element indispensable for life but required in extremely minute amounts.
atom - Answer The smallest unit of matter that retains the properties of an element.
subatomic particles - Answer The parts that make up an atom.
neutron - Answer A subatomic particle having no electrical charge (electrically neutral), with a mass of 1
dalton, found in the nucleus of an atom.
proton - Answer A subatomic particle with a single positive electrical charge, with a mass of 1 dalton,
found in the nucleus of an atom.
, electron - Answer A subatomic particle with a single negative charge and a minute mass, and move
around the nucleus of an atom.
atomic nucleus - Answer An atom's dense central core, containing protons and neutrons.
dalton - Answer A measure of mass for atoms and subatomic particles; the same as the atomic mass
unit, or amu.
atomic number - Answer The number of protons in the nucleus of an atom, unique for each element and
designated by a subscript.
mass number - Answer The sum of the number of protons and neutrons in an atom's nucleus.
atomic mass - Answer The total mass of an atom, which is the mass in grams of 1 mole of the atom.
isotope - Answer One of several atomic forms of an element, each with the same number of protons but
a different number of neutrons, thus differing in atomic mass.
radioactive isotope - Answer An isotope that is unstable; the nucleus decays spontaneously, giving off
detectable particles of energy.
energy - Answer The capacity to cause change, especially to do work (to move matter against an
opposing force).
potential energy - Answer The energy that matter possesses as a result of its location or spatial
arrangement (structure).
electron shell - Answer An energy level of electrons at a characteristic average distance from the nucleus
of an atom.