Q’S AND A’S
Element - answer- A substance that cannot be broken down to other substances by
chemical reactions; 92 elements
Compound - answer- A substance consisting of two or more different elements
combined in a fixed ratio
Elements in the human body - answer- oxygen, carbon, hydrogen, nitrogen, calcium,
phosphorus, potassium, sulfur, sodium, chlorine, magnesium
Essential Element - answer- elements that an organism needs to live a healthy life
and reproduce
Trace Elements - answer- required by an organism in only minute quantities
Energy - answer- the capacity to cause change
potential energy - answer- the energy that matter possesses because of its location
or structure
chemical bonds - answer- the attractive forces that hold atoms together
covalent bond - answer- the sharing of a pair of valence electrons by two atoms
single bond - answer- a pair of shared electrons
double bond - answer- A chemical bond formed when atoms share two pairs of
electrons
valence - answer- The bonding capacity of a given atom; usually equals the number
of unpaired electrons required to complete the atom's outermost (valence) shell.
Electronegativity - answer- The attraction of a given atom for the electrons of a
covalent bond; the more an atom has, the stronger it pulls shared electrons toward
itself
non polar covalent bond - answer- equal sharing of electrons
polar covalent bond - answer- A covalent bond in which electrons are not shared
equally
ions - answer- positively and negatively charged atoms
ionic bond - answer- the attraction between oppositely charged ions
, ionic compounds/salts - answer- compounds that contain ionic bonds
hydrogen bond - answer- noncovalent attraction between a hydrogen and an
electronegative atom
Van der Waals interactions - answer- individually weak and occur only when atoms
and molecules are very close together
reactants - answer- A starting material in a chemical reaction
products - answer- The elements or compounds produced by a chemical reaction.
chemical equalibrium - answer- When reactants are forming products at the exact
same rate products are forming reactants.
molecular shape - answer- The geometric shape formed by atoms bonded to the
central atom in a molecule
molecular function - answer- affects the structure and function of cells to determine
the trait
polar covalent bonds - answer- A covalent bond between atoms that differ in
electronegativity. The shared electrons are pulled closer to the more electronegative
atom, making it slightly negative and the other atom slightly positive.
polar molecule - answer- molecule with an unequal distribution of charge, resulting in
the molecule having a positive end and a negative end
Four emergent properties of water - answer- 1. Cohesive behavior
2. Ability to moderate temperature
3. Expansion upon freezing
4. Versatility as a solvent
cohesion - answer- Attraction between molecules of the same substance (water to
water)
surface tension - answer- A measure of how difficult it is to stretch or break the
surface of a liquid
Adhension - answer- attraction between molecules of different substances
kinetic energy - answer- energy of motion
thermal energy - answer- the total kinetic energy of all particles in a substance
temperature - answer- average kinetic energy
heat - answer- The energy transferred between objects that are at different
temperatures