Chemistry Final

atom

the smallest particle of an atom that still has the properties of that atom

What makes an atom neutral?

if there is the same number of protons and electrons

electron cloud

the space around the nucleus where the electrons orbit

electrons

negatively charged subatomic particles that help make up an atom

What determines which element an atom is?

the number of protons

neutrons

subatomic particles that do not have a charge

atomic number

the number of protons in an atom

mass number

the atomic mass of an atom (protons + neutrons)

1 amu =

1/12 of a carbon-12 atom

hyphen notation

name of the element - mass number of element

How are cations formed?

The atom loses electrons creating a positive charge

How are anions formed?

An atom gains electrons, creating a negative charge

What type of element generally forms cations?

Metals

What is the formula for atomic mass?

AMU= (mass A x A%) + (mass B x B%)

billard ball model

created by Democritius, the proposition that atoms existed

plum pudding model

created by jj thompson, discovered electrons

rutherford model

created by ernest rutherford, discovered that the middle of an atom was made up of a nucleus

Bohrs/Planetary Model

created by niels bohr, discovered electrons could jump between atoms by gaining or losing energy

The Quantum Mechanical model

created by multiple people, discovered the electrons moved in a fuzzy cloud and less of exact orbits

Who is attributed with the idea of arranging the known elements of his time into a model based on their chemical and physical properties?

Dmitri Mendelev

Who arranged the periodic table of elements by atomic number?

Henry Mosely

The periodic law states there is a periodic repetition of physical and chemical properties of the elements...

when they are arranged in order of increasing atomic number

valence electrons

electrons on the outer shell of an atom

What are the horizontal rows of the periodic table called?

periods

What do elements in the same periodic group have in common?

same valence configuration, same number of valence electrons, similar chemical properties

What do elements in the same periodic periods have in common?

same number of electron shells

What does PEL stand for?

Principal energy levels

How many elements are in the 2nd and 3rd rows of the periodic table?

eight

How many valence electrons do atoms in group 17 have?

7 or 17

What are the three classes of elements?

Metals, metalliods, non-metal

What elements are metalliods?

B, Si, As, Te, Ge, Sb

Which class of elements is dull, brittle, gains electrons, and are not good conductors?

non-metals

Which class of elements lose electrons, malleable, ductile, and are good conductors?

metals

most reactive group of nonmetals

17- halogens

completely unreactive periodic group

18- noble gases

which rows contain the transition metals?

3-12

most reactive group of metals

1- alkali metals

first row of the f-block elements

lathinides

class of elements that have both metal and nonmetal properties

metalliods

What is the periodic trend for atomic radius?

increases from left to right, increases down the group

What is the periodic trend for ionization energy?

increases from right to left across, increases up the group

What is the periodic trend for electronegativity?

increases from right to left across until the noble gases, increases up the group

what is ionization?

the amount of energy it takes to remove an electron from an atom

what is electronegativity?

the amount of attraction an element has to gaining electrons

Do metals have high or low electronegativity?

low

What element is most electronegative?

fluorine