CH2: Atoms+Elements

subatomic particles

smaller than atoms but not a unique substance

protons

positively charged subatomic particle, part of atom nucleus

neutrons

no charge/ neutral charge. part of atom nucleus

electrons

negative charge, ring of these surround atom nucleus

charge

electrical property; opposites attract, likes repel

atomic number

number of protons in an atom; distinguish elements

mass number

total number of protons and neutrons in an atom

Dmitry Mendeleev

1869 Russian Chemist; periodic table

chemical element

substance made up of one type of atom

macronutrients

needed in high amounts to sustain life-form

micronutrients

needed in small amounts to sustain life-form

electron cloud

Electrons orbit, or go around the, nucleus.

orbital

a region of space around the nucleus in which electrons are likely to be at any instant

chemical bonds

Attractive force between two atoms when their electrons interact

ionic bonds

strong mutual attraction between atoms of opposite charges. "steals" electrons from weaker atoms.

electronegativity

strong mutual attraction

covalent bonds

small difference in electronegativity, shared electrons, weaker bonds

hydrogen bonds

weakest bond, gives double helix in DNA

hydronium

oxygen with an extra 'stolen' hydrogen atom

hydroxide

oxygen missing a hydrogen atom

pH

the measure of the number of hydrogen atoms in a water-based fluid

acids

Dissociates to create hydronium ions

bases

Dissociates to create hydroxide ions