1.2- MASS NUMBER, ATOMIC NUMBER AND ISOTOPES

Question 1

What is the number of protons in the nucleus called?

Answer 1

atomic number or proton number

Question 2

What does it mean when the number of electrons and protons are equal?

Answer 2

atoms are electrically neutral

Question 3

What does the number of electrons in the outer shell of an atom determine?

Answer 3

chemical properties of an element (how it reacts) and what sort of element it is

Question 4

What does the atomic number define? (hint- identity)

Answer 4

the chemical identity of an element

Question 5

What do all atoms of the same element have in common?

Answer 5

same atomic number

Question 6

What is the total number of protons and neutrons in the nucleus called?

Answer 6

mass number

Question 7

What is responsible for almost all of the mass?

Answer 7

the nucleons because electrons weigh virtually nothing

Question 8

What is an isotope?

Answer 8

atoms with the same number of protons but different numbers of neutrons

Question 9

How do different isotopes of the same element react and why?

Answer 9

react chemically in exactly the same way as they have the same electron configuration

Question 10

Why do atoms of different isotopes of the same element vary in mass number?

Answer 10

because of the different number of neutrons in the nuclei