Chemistry Chapter 3 Section 3

Isotopes are atoms of the same element that have different ___________.

Masses

What is equal to 1.00 mol of carbon-12?

a. 6.022 x 10^23 b. 12.0g of carbon

The number of protons in the nucleus of an element is its ___________ number.

atomic

The units of molar mass are __________________________________.

grams/mole

Compared with a mole of lead atoms, a mole of iron atoms _____________________________________________________________.

has the same number of atoms

The total number of protons and neutrons in the nucleus of an isotope is called its _________ number.

mass

Neutral atoms of the same element can differ in __________.

mass number

The _____________________ is the total number of protons and neutrons in an atom of an element.

mass number

The atomic symbol for beryllium 9/4 Be, indicates that the ________________.

mass number is 9 and atomic number is 4

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

mole

To take a weighted average of all the naturally occurring isotopes of an element in order to arrive at an average atomic mass, you would _____________________________________________________________________________________________________________________.

multiply the mass of each isotope by the decimal fraction representing its abundance naturally then add all these products together.

One mole is defined as ____________________________________________________________________________________________________________________________________________________________.

the amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12.

The molar mass of an element is numerically equal to _________________________________________________________________________.

the elements average atomic mass

The atomic number of an element is

the number of protons in each atom of the 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

What is the definition of one atomic mass unit?

1/12 of the mass of a carbon-12 atom

A neutral atom of silicon-30 contains 14 protons. How many electrons does it have?

14

How many protons, electrons, and neutrons are there in an atom of chlorine-37?

17 protons, 20 neutrons, 17 electrons

The isotope uranium-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 19 neutrons. Its mass number is ___________.

38

Carbon-14 has 8 neutrons. What is the atomic number of carbon-14?

6

Atoms of one element that have different masses are called __________.

Isotopes