1. Basic Chemistry Flashcards
(25 cards)
The functional unit of matter
Atoms
Anything that occupies space and has mass
Matter
The core of the atom, consists of two kinds of subatomic particles
Nucleus
Positive charge
Proton
No charge
Neutron
99.9% of the atoms mass is found in _____
The nucleus
Negatively charged
Electrons
Electrons are found moving about the ____ at ____
- Nucleus
2. Tremendous speeds
These electrons are found in _____
The electron cloud
The electron cloud is broken down into separate sections called ____
Shells or levels
Each of the surrounding levels:
1st level _____
2nd level _____
3rd level _____
- ) 2 electron max
- ) 8 electron max
- ) 8 electron max
Electrons near the nucleus have ____ but those away from the nucleus have ____
- Lower energy
2. Higher energy
In an uncharged atom:
The number of protons = the number of ____
The charges ____ each other
The net charge on an atom is ____
Electrons
Offset
0
A substance that __________ into simpler kinds of matter is an element
Cannot be broken down chemically
Each element has a symbol, they are all represented in the ________
Periodic Table
The number of protons in a nucleus
Atomic number
The sum of the protons and neutrons in an atom vs. average of all the neutrons
Mass number/atomic weight
Atoms of the same element that have a different number of neutrons
Isotopes
Isotopes have:
The same number of _____
Different ______
Protons
Atomic mass
Two or more elements that are joined by CHEMICAL BONDS
Compounds
In compounds the proportions of the individual atoms are ____
Fixed
____ will always be in the same proportion for a substance
Element
H2O and NaCl are examples of ____
Compounds
Shows the proportions of atoms that form compounds
Chemical formulas
