Vocabulary
define atoms
the basic unit of life
what is a covalent bond
sharing of electrons
solvent
equations that model what happens in a chemical reaction
chemical equations
What is the exact boiling point of water (in *C)?
100*C
define ionic bonds
attraction between oppositely charged ions/transfer of electrons
substance made up of one type of atom and cannot be broken into simpler substances by ordinary chemical means
element
is water a polar or non-polar molecule?
non-polar
what is the amount of energy needed to break a specific chemical bond called?
bond energy
What is the 8th element on the periodic table of elements?
Oxygen (O)
define molecules
two or more atoms held together by covalent bonds
when is an atom most stable
when its it has a full outer valence shell of electrons (8, 2)
what is adhesion
the attraction among molecules of different substances
the amount of energy that needs to be absorbed to start, or activate, a chemical reaction
activation energy
How many moons does the Sun have?
None. The Sun has no moons.
define polar molecules
Molecules with two covalent bonds
what are atoms that have gained or lost electrons called
ions
what is cohesion
the attraction among molecules of a substance
in what reaction do the products have lower bond energies than the reactants?
exothermic reaction
What is the speed of light on planet Earth? Convert your answer to km/sec.
300,000 km/s
define compounds
substances composed of atoms of two or more different elements bonded together in specific ratios
Atoms that gain electrons become _____ charged ions.
Atoms that lose electrons become _____ charged ions.
negatively, positively
how does cohesion help an insect walk on water
the water molecules stick together, forming a film on which the insect can walk
what are the catalysts used in living organisms called?
enzymes
Molecules of what elements are fast enough to escape Earth's gravitational pull?
molecules of Hydrogen (H) and Helium (He)