Ch. 4 Vocab (Sec. 1-3) Flashcards
0
Q
Atom
A
The smallest particle of an element that retains the properties of the element
1
Q
Dalton’s Atomic Theory
A
- Matter is composed if atoms
- Atoms are indivisible & indestructible
- Atoms of a given element are identical in size, mass, and chemical property
- Atoms are individual to each element
- Atoms combine to form compounds
- In reactions, atoms are separated, combined, or rearranged
2
Q
Cathode Ray
A
Radiation that travels from the cathode to the anode of a cathode-ray tube
3
Q
Electron
A
Negatively charged particles found in all forms of matter
4
Q
Nucleus
A
A tiny, dense region in the center of the atom
5
Q
Proton
A
A subatomic particle carrying a positive charge
6
Q
Neutron
A
A subatomic particle that carries no electrical charge
7
Q
Atomic number
A
The number of protons in an atom
8
Q
Isotope
A
Atoms with the same number of protons but different numbers of neutrons
9
Q
Mass number
A
The sum of the number of protons and neutrons in the nucleus
10
Q
Atomic mass unit (amu)
A
One-twelfth the mass of a carbon-12 atom
11
Q
Atomic mass
A
The weighted average mass of the isotopes of an element
