Chapter 2 Flashcards
occupies space and has mass
matter
quantity of matter in an object
mass
purest form of matter
element
fundamental unit of matter
atom
3 parts of an atom
proton, neutron, electron
protons and neutrons are found in
the nucleus
protons and neutrons have
one atomic mass unit
electrons are found in
clouds around the nucleus
electrons have
no mass
number of protons in the nucleus
atomic number
number of protons and neutrons
atomic weight
different number of neutrons than original
isotopes
has the same number of protons and electrons
isotopes
unstable and emits energy
radioactive isotopes
atoms coming together forming molecules
chemical bonding
what are the 3 types of bonds?
- Covalent
- ionic
- hydrogen
atoms share electrons (holding hands)
covalent
atoms transfer electrons (fist bump)
ionic
hydrogen bonds can only happen when
a covalent bond has already happened
attractions between a positively charged hydrogen and a weak, negatively charged atom (like oxygen)
hydrogen bond
how many electrons does the first energy level hold?
2
how many electrons do the outer energy levels hold?
8
an element is more reactive when…
it needs more electrons to become stable