AP Week 2 Lecture

What is chemistry?

The scientific study of matter

What is matter?

anything that takes up space and has mass

Chemistry studies the ______ between matter

interactions

3 physical phases of matter

gas, liquid, solid

what are elements?

pure forms of matter that cannot be broken down to a simpler form

Can elements consist of 2 of the same atom?

yes

how many elements are there?

118

how many naturally occurring elements are there?

92

what are elements composed of?

atoms

what is an atom?

the smallest unit of matter that retains its chemical and physical properties of that element

an atom is composed of what

3 subatomic particles

what are the 3 subatomic particles that make up an atom?

proton, neutron, electron

Do protons and neutrons have equal mass?

yes

what are the two regions of an atom

nucleus, electron cloud

what is the electron cloud

the entire volume where the electrons are found

where are protons and neutrons located in the atom?

nucleus

what part of the atom contains most of the mass?

nucleus

what is the number of protons in an element called

atomic number

what identifies an element?

the atomic number

what are isotopes of an element?

they have the same number of protons, but different number of neutrons

what is the mass number

number of protons + number of neutrons

can mass number vary between isotopes?

yes

do isotopes have the same chemical properties as the initial element?

yes

what is a radioactive isotope?

an unstable isotope

How do you know if an atom is neutral?

number of protons = number of electrons

what is an atom called when it loses or gains an electron?

ion

in the Bohr model of an atom, how many electrons can the innermost shell hold?

2

in the Bohr model of an atom, how many electrons can every shell besides the innermost hold?

8

what is the outermost electron shell called?

valence shell

what is ionic bonding?

when two atoms exchange electrons. one loses, one gains

what are electron shells?

specific regions where electrons are found

which electron shells are involved in bonding?

outer shells

how do atoms link together?

chemical bonds

how is a chemical bond formed?

breaking a bond, rearranging atoms, and forming new bonds

what are linked atoms called?

molecules

how many electrons need to be in the valence shell for the atom to be stable and unwilling to bond?

8

ionic bonds transfer electrons and form a ______

compound

what kind of structures do ionic bonds form?

crystalline, lattice like

are ionic bonds weak or strong?

weak

can ionic bonds dissolve in water?

yes

what is a covalent bond?

share a pair of electrons

what does a covalent bond form

molecules

what is a single bond?

sharing 1 pair of electrons

what is a double bond?

sharing 2 pairs of electrons

what is a triple bond?

sharing 3 pairs of electrons

are covalent bonds strong or weak

strong

do shells overlap in covalent bonds?

yes

do covalent bonds need to share electron pairs equally?

no

nonpolar bond

equal sharing of electrons

polar bond

unequal sharing of electronsw

what does a polar bond result in?

partial charges

chemical reaction

breaking, rearrangement, and formation of chemical bonds

what drives the processes of life?

chemical reactions

intermolecular forces

when two molecules interact with each other

what are hydrogen bonds?

weak, polar bonds. partial negative of a molecule is attracted to partial positive hydrogen