college chem chapter 2 quiz

1000 BC

chemistry was used to mix and melt metals to make stronger weapons

Greeks

first to come up with the fact that the atom is the smallest indivisible particles

Alchemy

turning cheap metals into gold

Democratis

came up with the word for atom: “atomost”

Lavoiser

law of conservation of mass: mass is neither created nor destroyed

Proust

Law of definite proportions: all compounds have exactly the same elements by mass

Dalton

Law of multiple proportions: elements will always combine in whole numbers

Daltons 4 postulates

1. all things are made up of tiny particles called atoms

2. the atoms of elements are identical (incorrect, ions)

3. chemical compounds combine when different atoms of elements combine

4. chemical reactions involve reorganization atoms

Thomson:

cathode ray tube, found that electrons have a negative charge

Millikan:

oil drop experiment: found the mass of an electron: 9.11×10^23

rutherford:

gold foil experiment: found that atoms have a dense center with a positive charge, nucleus

current view of the atom:

a nucleus containing positive protons and neutral neutrons, this has electrons surronding it

atomic number:

number of protons in an element

the density inside the nucleus is

HIGH

mass number:

protons + neutrons

isotope of hydrogen with 1 proton, 0 neutrons, and a mass number of 1

protium

isotope of hydrogen with 1 proton, 1 neutron, and a mass number of 2

deuterium

isotope of hydrogen with 1 proton, 2 neutrons, and a mass number of 3

tritium

metals have a ____ charge

positive

metals tend to ______ electrons

lose

properties of metals

conductors, luster, malleable(pressed), ductile(stretched), high melting point and density

nonmetals tend to ______ electrons

gain

nonmetals have a _______ charge

negative

properties of nonmetals

complete opposite of metals

chemical bonds:

forces that hold together atoms in a compound

covalent bond

occurs between a nonmetal and nonmetal

covalent compounds are called

molecules

7 diatomics

H, N, O, F , CL, Br, I

ionic bonds:

form between nonmetals and metals

an ionic bond always has a ___ ion and __ ion

cation and anion

cation

positive

anion

negative

come first when naming acids

hydrogen

a polyatomic with the ending of ate has an ending of ___ in an acid

ic

a polyatomic with the ending of ite has the ending of ___ in an acid

ous

when you don’t have a polyatomic or oxygen in an acid, you use the prefix

hydro

atomic radius

size of an atom

left to right, atomic radius

decreases because the more protons there are the stronger pull there is to the electrons, they are closer to the nucleus and shrink the atom

top to bottom atomic radius

increases because the more shells, the bigger the atom

ionization energy

amount of energy needed to remove an electron

left to right, ionization energy

increases because as the electron gets closer to the nucleus, the more force it takes to remove it

top to bottom, ionization energy

decrease because the electrons are farther from the nucleus due to the extra shells, this makes them easier to be removed

electronegativity

how strong an atom attracts another atom in a chemical bond

left to right, electronegativity

increases because the more protons an atom has, the positive charge of the nucleus attracts atoms more

top to bottom, electronegativity

decreases, the farther away the electron is from the nucleus, the weaker pull it has

exceptions to electronegativity:

noble gases don’t have an electronegativity because their valance shell is already full

non-metallic charcter

the more an element acts as a nonmetal, tends to gain electrons

left to right, nonmetallic character

increases, as you move across, the elements start to gain electrons

top to bottom, nonmetallic

decreases because as you go down, the elements tend to have a weaker pull so they lose electrons, not gain

metallic character

how much an element acts as a metal, tend to lose electrons, have a positive charge

left to right, metallic

decreases, as you move across the elements start to gain, not lose

top to bottom, metallic

increases because the bigger atoms have a weaker pull so they lose electrons easier

columbic attraction:

the forces between 2 atoms with opposite charges

left to right, columbic attrction

increases because the electrons have a stronger pull

top to bottom, columbic attraction

decreases, farther away electrons get, weaker the pull they have

valence electrons:

outer shell of electrons

left to right, valence

increases by 1 because electrons are added by shell, one at a time

top to bottom, valance

stays the same because the groups/families have similar properties