Lecture 5: Chemistry Review Flashcards
(100 cards)
Atomic number (Z)
Number of protons, determines the identity of the atom
What are ions?
Atoms/groups of atoms bonded together with a net charge
Two types of ions
- Cations
- Anions
Cation
Positively charged ion
Anion
Negatively charged ion
Elements contain…
Only 1 type of atom
Compounds contain…
More than one kind of atom in a fixed ratio by mass
What are molecules?
Groups of atoms chemically bonded together into a discrete unit by covalent bonds; neutral charge
What are ionic compounds?
- Contain both positively and negatively charged ions with no identifiable units
- Attracted by charge and are not molecules
Can a substance be both a molecule and an element?
Yes
What is a physical change?
No change in the chemical makeup (i.e.: melting ice)
What is a chemical change?
Always makes a chemically different substance (i.e.: 2H2O —> 2H2 + O2)
What is a physical property?
May be observed/measured without changing the chemical makeup
What are two types of physical properties?
- Intensive
- Extensive
What is an intensive physical property?
Integral to the material, regardless of amount (i.e.: color)
What is an extensive physical property?
-Depends on sample size (i.e.: volume)
What is a chemical property?
Describes the type of chemical changes the material tends to undergo (i.e.: flammable)
Boiling water to steam
Chemical property
Liquid
Intensive physical property
Mass
Extensive physical property
What are substances?
Pure materials that can’t be physically separated into simpler components; can be compounds or elements
Throughout all samples, the chemical and physical properties of substances are ___
Uniform
What is a mixture?
2 or more pure substances
Physical processes can separate the mixture into ___
Simpler substances