25 questions
The atomic mass of an element is the ___.
average of the mass number and the atomic number for the element
weighted average of the masses of the isotopes of the element
total mass of the isotopes of the element
total number of subatomic particles in the nucleus
Magnesium exists as the three isotopes shown. What is the average atomic mass of magnesium?
20.74 amu
22.56 amu
18.39 amu
24.31
What determines if an element is reactive or not?
number of protons
number of valence electrons
mass number
number of core electrons
What group on the periodic table is stable?
Group 1
Group 2
Group 7
Group 8
How do metals achieve stability?
losing electrons
adding electrons
losing protons
adding protons
How do nonmetals achieve stability?
losing electrons
adding electrons
losing protons
adding protons