chemistry

accuracy

how close of a measurement we are to a correct value or target

precision

closeness of two and measurements to each other

quantitative

discrete, or counting, or continous or measurement. numerical .Quantitative refers to data that can be expressed as a number, allowing for statistical analysis and comparison.

qualitative

descriptive data involving sentences, based on observations. Qualitative refers to data that describes characteristics or qualities, often expressed in words rather than numbers, allowing for analysis based on subjective interpretation.

subatomic particles

smaller than an atom

proton

1.00728 = 1amo nucleus positively charged subatomic particle

electron

0.000549=0 amu orbital negatively charged subatomic particle

nuetron

1.00867=1 amu, nucleus neutral subatomic particle in the nucleus

amu

atomic mass unit

isotope

same element that have a diff. mass due to varying numbers of neutrons.

periodic law

elements, when listed by their atomic number, their chemical and physical properties repeat periodicaly

valence electrons

Electrons in the outermost shell of an atom that determine its chemical properties and bonding behavior.

aufbau principal

electrons will fill the lowest energy level first, then move to the higher ones

trends

predictable pattern or change in a particular direction

reactivity

how easily an element will combine or interact with other elements to form compounds or molecules

atomic radius

size of atom, #of energy levels, amount of proton. determines size

electronegativity

the ability of an atom to attract an electron in the outermost energy level. a change in energy levels

compound

a substance in which 2 or more different elements are bound together

molecues

diatomics/two of the same element sharing an electron

polyatomics

group of atoms bonded that act as a single atom

ends in ite/ate

written as:

sodium carbonate: Na(2)Co(2)

more than one PAI needed:

Magnesium Nitrate

Mg(NO>3)>2

ionic compounds

metals and nonmetals

electrons are transferred

compound is neutral

covalent bonds

nonmetal and nonmetal

electrons shared

compound is neutral

diatomic elements

two-atom elements

Br,I,N,Cl,H,O,F only

always X>2, as not enough electrons on own

chemical reation

change that is chemical occurs when atoms rearrange and form new substances

reactants

original substance in a chemical reation

products

the new substance made by a chemical reaction