first chem test sep/18 2015

Question 1

element

Answer 1

a substance that cannot be broken down by ordinary chemical means

Question 2

chemical reaction

Answer 2

the transformation of a substance or substances into one or more new substances

Question 3

law of conservation of mass

Answer 3

mass is neither destroyed nor created during ordinary chemical reactions

Question 4

The 2 important concepts from Dalton’s theory

Answer 4

one all matter is composed of atoms and two atoms of any one element differ in properties from another element remain unchanged

Question 5

atom

Answer 5

the smallest particle of an element that retains the chemical properties of that element (contains nucleus and electron cloud)

Question 6

nucleus

Answer 6

a very small region in the center of an atom that contain one or more proton and usually one or more neutrons

Question 7

proton

Answer 7

positively charged particle located in the center of the nucleus of an atom

Question 8

electron

Answer 8

negatively charged particle that surrounds the nucleus of the atom

Question 9

neutron

Answer 9

neutrally charged particle located in the center of the nucleus

Question 10

subatomic particle

Answer 10

the term for neutrons, protons, and electrons

Question 11

nuclear force

Answer 11

these short range proton-neutron, proton-proton, and neutron-neutron forces that hold the nuclear particles together

Question 12

location

Answer 12

proton and neutron are in the nucleus and the electrons surround the nucleus

Question 13

charge

Answer 13

electron = - proton = + neutron = 0

Question 14

relative mass

Answer 14

electon = 0 proton = 1 neutron = 1

Question 15

important number of protons

Answer 15

determines the atom’s identity

Question 16

charge of an atom

Answer 16

0

Question 17

electron cloud

Answer 17

a cloud of negative charge made of protons that surrounds the nucleus of an atom

Question 18

atomic number

Answer 18

the number of protons in the nucleus of each atom of that element

Question 19

isotopes

Answer 19

atoms of the same element that have different masses

Question 20

mass number

Answer 20

the total number of protons and neutrons in the nucleus of an isotope

Question 21

hyphen notation

Answer 21

the mass number is written with a hyphen after the name of the element

Question 22

nuclear symbol

Answer 22

mass number over atomic number written like a fraction with the name of the element written next to it

Question 23

calculating number of neutrons

Answer 23

mass number minus atomic number

Question 24

nuclide

Answer 24

a general term for any isotope of any element

Question 25

atomic mass unit (amu)

Answer 25

exactly 1/12 the mass of a carbon 12 atom

Question 26

isotopes and chemical behavior

Answer 26

although isotopes have different masses they do not differ in chemical behavior

Question 27

average atomic mass

Answer 27

the weighted average of the atomic masses of the naturally occurring isotopes of an element

Question 28

relationship between mass number and relative atomic mass of a given nuclide

Answer 28

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Question 29

idea behind calculating average atomic mass

Answer 29

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