Bio 2 Unit Quiz

matter

anything that has mass and takes up space, made of atoms

atoms

the smallest unit of matter that can't be broken down (w/o releasing charged subatomic particles)

solid, liquid, and gas

What are the three forms of matter?

solid

definite shape and volume, particles are close together and organized, particles vibrate, and the highest density

liquid

no definite shape but definite volume, particles have some space between them, particles slide past each other middle density

gas

no definite shape or volume, particles are very spaced out w/ little to no organization, particles are fast moving, the least density

ions

atoms have a +/- charge

mass number

protons + neutrons, the weight of atom

atomic number

the number of protons

protons, neutrons, and electrons

What are the three charges that make an atom?

protons

positive charge (+), located in the nucleus, determines which element it is, have about the same weight has neutrons

neutrons

no charge, located in the nucleus, the change of ______ means the change to the mass number, same elements with different mass (isotope)

electrons

negative charge (-), no weight, number of electrons change (ions), located in electron cloud (shells)

2, 8

How many electrons are in the first shell? How many electrons are in all the other shells?

cation

a positively charged ion

anion

a negatively charged ion

element

a substance that can't be broken down to other substances by ordinary chemical means

compound

a substance consisting of two or more different elements combined in a fixed ratio

atomic mass

the weight (protons + neutrons)

isoptope

an atom that has the same number of protons but a different number of neutrons

valance shell

number of electrons present in the outermost shell, determines the chemical properties of an atom

chemical bonds

when two atoms with incomplete outer shells interact (give up, share, and accept electrons), they will both end up with a completed out shell and then the atoms stay close together

covalent bond

a chemical bond that involves sharing a pair of electrons between atoms in a molecule, the strongest bond, between nonmetals (right side of PT)

valance

bonding capacity of an atom

molecule

two or more atoms held together by covalent bonds

electronegativity

measure of its attraction for shared electrons

non polar covalent bond

equal sharing of electrons, equal electronegativity of two atoms, no charge

polar covalent bond

a bond when both atoms differ in electronegativity, unequal sharing of electrons, slightly positive and slightly negative

ionic bond

receiving/losing of an electron, metal with a nonmetal, a large difference in electronegativity, middle bond

hydrogen bond

must be paired with two polar molecules, function in proteins, properties of water, weakest

they have slow particles, more stable

What happens to hydrogen bonds in cold temp?

fast particles, least stable

What happens to hydrogen bonds in high temp?

solvent

a substance that does the dissolving

solute

substance that gets dissolved

solution

solute + solvent

polar (attracted to each other) and ionic (the charge of the bond)

polar bonds can dissolve what other bonds and why?

intramolecular

existing or taking place within a molecule (covalent and ionic bonds)

intermolecular

existing or acting between molecules (hydrogen bond)

non polar bonds (they have no charge)

What can polar bonds no dissolve?

surface tension

intermolecular force, a measure of how difficult it is to stretch or break the surface of a liquid

high specific heat

it needs to absorb a lot of energy before its temperature changes

chemical reactions

breaking existing chemical bonds

cohesion

the tendency of a molecule to stick together (trees get their nutrients)

adhesion

clinging of one substance to another

thermal energy

the energy associated with the random movement of atoms and molecules

acid

a substance that donates hydrogen ions to solutions

base

substance that reduces the hydrogen ion

pH scale

how acidic or basic a solution is

buffers

organic substances that maintain a constant pH over a given range by neutralizing the effects of hydrogen ions.

water

What form on Earth has all three matters naturally

they already have a full outer shell

why don't noble gases form covalent bonds

metals don't hold onto electrons very well

Why don't metals form covalent bonds

the ice is less dense than the water, the water is heavier so it displaces the ice

Why can ice float on water even though it's a solid?