Chapter 1 Review Flashcards
What are atoms? Molecules?
Atoms: basic particle that composes ordinary matter
Molecules: matter (two or more atoms) that are bonded together in a definite ratio and specific orientation
What are the states of matter?
Solid: fixed shape and volume (not easily compressed)
Liquid: moving around, no fixed shape, fixed volume
Gas: no fixed shape or volume (easily compressed)
What is a pure substance? An element? A compound? A mixture?
Pure substance: matter made by a single type of particle and cannot be separated by a physical technique
Element: matter made of only one type of atom, cannot be broken down further
Compound: matter made of 2 or more elements in a defined ratio
Mixtures: two or more pure substances that can be separated by physical means
What is a homogenous mixture? A heterogenous?
Homogenous: mixture that is entirely uniform
Heterogenous: mixture that is not entirely uniform
What are the four postulates of atomic theory?
1) all matter is made of atoms
2) all atoms of an element are identical, atoms of different elements have different masses/properties
3)compounds are formed by the combo of two or more elements in a simple, whole number ratio
4) a chemical reaction may only involve the combo, separation, or rearrangement of atoms (matter cannot be created or destroyed?
What are the basic laws of chemistry?
Law of conservation of mass: matter cannot be created or destroyed (mass at start=mass at end)
Law of definite proportions: all samples of a given compound are made the same way
Law of multiple proportions: combine things in a whole number (we cannot split atoms)
What are the particles of an atom?
Electron (-1 charge, no mass), proton (+1 charge, mass), neutrons (no charge, mass)
What dictates the identity of an atom?
The proton count
Rutherford model of an atom?
1) mostly empty space
2) most mass of an atom is in the nucleus
3) the nucleus contains all of the positive charged particles (protons)
4) atoms of elements are neutral, as the proton number must be equal to the number of electrons
5) neutrons keep the protons stable (Chadwick 1932)
What is an atomic number?
The number of protons in nucleus of an atom
What are each of these parts?
A 12
X —————-> C
Z. 6
A: atomic mass # (protons + neutrons)
Z: atomic number (the protons)
What is a cation? An anion?
Cation: molecule/element with a positive charge
Anion: molecule/element with a negative charge
What is an isotope? Allotrope?
Isotope: elements that contain the same number of protons but a different number of neutrons
Allotrope: elements with a different structure
What is an atomic mass?
Average mass of an element (under element symbol on periodic table)
What is a mole?
An si unit for measuring the amount of a substance
