Chemistry Chapter 3 Section 3

the number of protons in the nucleus of an element is called its ______ number

atomic

the units of molar mass are _____ per ____

grams/mole

compared with a mole a lead of atoms, a mole of iron atoms _________________

has the same number of atoms

atoms of one element that have different masses are called ________

isotopes

the total number of protons and neutrons in the nucleus of an isotope is called its ____ number

mass

the ____ ______ is the total number of protons and neutrons in an atom of an elephant

mass number

isotopes are atoms of the same element that have different ______

masses

the amount of a substance that contains a number of particles equal to the number of atoms in exactly 12 g of carbon-12 is referred to as a ____

mole

the molar mass of an element is numerically equal to __________________

the element average atomic mass

neutral atoms of the same element can differ in ___ ____ ______

the mass number

the atomic number of an element is ___________________________

the number of protons in each atom of an element

the average atomic mass of an element is ___________________________________

the weighted average of all naturally occurring isotopes of the element

hydrogen that is composed of atoms with two neutrons is called _______

tritium

a neutral atom of silicon-30 contains 14 protons. how many electrons does it have? __

14

an atom of potassium-235 has 92 protons and 143 neutrons. therefore, its mass number is ___

235

the nuclear symbol for uranium-235 should be written as _____

235/92 U

the atomic number of nickel-60 is 28. how many neutrons does this isotope have? __

32

An atom of potassium has 19 protons and 20 neutrons. Its mass number is __

38

carbon-14 has 8 neutrons. what is the atomic number of carbon-14? __

6

the atomic symbol for beryllium, 9/4 Be, indicates that the mass number is __ and the atomic number is __

9, 4