chemistry unit. 2 test

4 ideas behind daltons theory of an atom

4 ideas behind daltons theory of an atom

1. elements are composed of extremely small particles called atoms

2. all atoms of a given element are identical, same size, mass, and chemical properties. each element had differ atoms

3. compounds are composed of atoms of more than one element.

4. a chemical reaction involved in only the separation, domination, or rearrangement of atoms - doesn’t result in destruction of atoms

law of definite proportions

different samples of the same atom compound always contain its constituent elements in the same proportion by mass

ex. h20 - ratio: 2o2 :1 H

law of multiple proportion

if two elements can combine to form another compound the masses of one element can combine with a fixed mass of another element are in ratios of small whole numbers

example: h2o2 - 1:2 and 1:3

law of conservation. of mass

matter can be neither destroyed or created

subatomic particles

electron- negative

proton - positive

neutron - neutral

where do u find electrons, protons, neutrons

electrons: outer rings of an atom

protons and neutrons: in nucleus

what subatomic particles contribute to mass

protons and Neutrons

what’s an atomic number

number of protons in a nucleus

each element has its own number, equaled to number of electrons

alkali metals

highly reactive, high thermal and electrical conducted

alkaline earth metals

highly reactive, good conductor of electricity

halogens

all form acids when combined with hydrogen, electronegative, highly toxic

noble gases

least reactive, colorless, odorless, non flammable

what’s a metal

good conductor of heat and electricity

what’s a nonmetal

poor conductor of heat and electricity

metalloid

has properties that’s intermediate of both nonmetals and metals

valence electron

outer electrons of an atom

where?- most outer ring

determine charge of atom

ionization energy, describe trend

amount of energy required to remove an electron

highest on the right side (low to high, left to right)

atomic radius

radius of atom

element with more protons will pull in electrons - opposites attract

less protons pull in less

electron affinity

atom more easily accepts electrons

going more to the right, elements want to fill their shell

what shape does a solid sample of an ionic compound arrange itself into

lattice 😄

cation

positively charged ions, METAL, LOSES electrons

anion

negatively charged ion, usually nonmetal, gains electrons