Atoms Flashcards
What is an atom?
The smallest particle of an element
Description of an atom
a positively charged nucleus circled by widely spaced negatively charged particles.
A particle of matter smaller than an atom?
Subatomic particles (protons, electrons, neutrons)
Proton
A large subatomic particles with positive charge
Electron
A very small subatomic particle with negative charge
Neutron
A large subatomic particle with no charge
Nucleus
The center part of an atom, with an overall positive charge
Elements
A substance made up of just one type of atom
Compounds
A substance made up of different types of atoms (molecules in a compound range from small to large)
Charge
An electrical property of matter
Net Charge
Overall electrical charge of a particle
Neutral Particle
A particle with zero net charge
Neutral Charge = ?
equal number of protons and electrons
positive ion
an atom or molecule with net positive charge
forms when a neutral atom loses electrons, so it has more protons than electrons
negative ion
an atom or molecule with net negative charge
forms when a neutral atom gains electrons, so it has more electrons than protons
Ca2+
a calcium ion that is missing two electrons compared to the neutral calcium atom
Cl-
A chlorine ion that has one extra electron compared to the neutral chlorine atom
atomic number
number of protons in an atom
ion
an atom or molecule with a net charge
- positive or negative substance
- may be one atom or a group
- positvies ions have lost electrons
- negative ions have gained electrons
three types of chemical bonds
ionic, covalent, metallic
ionic bond
metal - non-metal
ionic bonds are formed by the transfer of electrons
ionic compound forms - metal atoms turn into positively charger cations
covalent bond
non-metal - non-metal
metallic bond
metal - metal
electron cloud model
a model of the atom in which electrons move freely
planetary model
a model of the atom in which electrons move in defined orbits
mass number
the number of protons and neutrons in an atom
when two atoms have the same number of protons
belong to the same isotope
stable isotope
an isotope in which the nucleus is not likely to break apart
unstable isotope
an isotope in which the nucleus is likely to break apart
radiation
the energy or particles released during radioactive decay
(alpha, beta, gamma radiation)
radioactive decay
the process of unstable atoms releasing radiation
acids
- a mixture formed when one substance dissolves in another
- to undergo chemical change
- able to break down or destroy substances by reacting with them
- having a sharp, tangy or unpleasant taste or smell
H+ ions
acids
Hydrogen ion
a positive ion formed when a hydrogen atom loses its one electron (H+)
Hydroxide ion
a negative ion made up of an oxygen atom bonded to a hydrogen atom (OH-)
Bases
an atom or molecule that has gained or lost electrons giving it an overall electrical charge
OH- (hydroxide ions)
Bases
Cation
a positively charged ion that is formed when a metallic element loses one or more electrons
Anion
ions that are negatively charged, formed when a metallic element gains one or more electrons
valance shells
the shells surrounding the nucleus that hold the electrons
valance electrons
are located in the outermost occupied shell of an atom
