Chem unit 2 quiz 1

subatomic particles atomic #, atomic mass, mass # Isotopes, Ions

Protons

positive subatomic particles in the nucleus. The # of protons identifies the atom, and is equal to the atomic number and the nuclear charge

Symbol: P⁺ Mass: 1 Charge: 1⁺

Electrons

negative subatomic particles in the orbitals. The number of electrons is equal to the number of protons in an atom only

Symbol: e⁻ Mass: 1/1837th Charge: 1⁻

Neutrons

neutral subatomic particles in the nucleus. The number of neutrons identifies the isotopes

Symbol: n⁰ Mass: 1 Charge: 0

Subatomic particles

protons, electrons & neutrons

Atomic number

the number of protons and the nuclear charge of an atom, identifies the atom

Atomic mass

the weighted averaged of all the naturally occurring isotopes of an atom, always a decimal

Calculating Atomic Mass

atomic masses are weighted averages that take into account the natural abundances of each isotope

Mass number

the protons and neutrons in the nucleus. Equal to the number of nucleons. Identifies an isotope, always a whole number

Isotope

atoms of the same elements with a different number of neutrons. Mass number and number of nucleons will be different as well. Same atomic #, different mass # or same # of protons, different # of neutrons

Most common isotope

the isotope that exists in the greatest abundance. Round the atomic mass and you will get MCI

Atomic mass unit (amu)

the unit of measure for a subatomic particles, 1/12th the mass of Carbon

Ion

a charged particle formed by the loss of gain of an atom’s electrons

Dalton

atom is a solid indivisible sphere

Thompson (cathode ray tube)

discovered the electron. Electrons are randomly embedded in positive atom, also called the plum pudding model

Rutherford (gold foil experiment)

shot alpha particles at gold foil and most went through the foil. Concluded that atom is mostly empty space with a dense, positive nucleus

Bohr (planetary model)

used bright line spectra to determine the electrons are in orbits (specific, circular path around the nucleus)

Electron cloud/ wave mechanical model/ modern model

electrons are in orbitals

Orbitals

region where you are likely to find an electron