Chapter 2.1 Flashcards
(20 cards)
What is Matter?
Anything that has mass and occupies space
3 states of matter
1.solid
2.liquid
3.gas
What is matter composed of?
Elements
What is an Element?
Composed of one type of atom; can’t be broken down
What 6 elements make up 95% of body weight (CHNOPS)
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur
What are electron shells?
Orbiting clouds around nucleus
What is an atomic number?
Number of protons
What is mass number/atomic mass?
sum of protons and neutrons
What are Isotopes?
are atoms of the same element that differ in the number of neutrons
What is an radioactive isotope?
give off energy in the form of rays and subatomic particles
Electrons
Determine chemical behavior of atoms
What is a Valence shell and why is it important?
The outermost energy shell.
It is important b/c it determines the atom’s chemical properties
octet rule
the ourtermost shell is most stable when it has 8 electrons
Chemically Reactive
When an atom does not have its valence shell filled
Compound
A molecule containing at least 2 different elements
How are bonds between atoms in molecules caused?
By interaction between electron in the outermost energy shell.
Chemical Reaction
the process of bond formation
Ion
an atom that has lost or gained an electron
Ionic bond
when electrons are transferred from one atom to another
Salts
solid substances that usually separate and exist as individual ions in water
