Relative mass - 2.2 - (1)

Question 1

What does the strong nuclear force which holds together protons and neutrons come at the expense of?

Answer 1

the loss of a fraction of the mass of the protons and neutrons

Question 2

Who came up with this fact that protons and neutrons lose a fraction of their mass?

Answer 2

albert einstein over 100 years ago

Question 3

What is the small amount of mass lost called?

Answer 3

mass defect

Question 4

How do chemists calculate the mass of atoms?

Answer 4

a standard isotope is needed to base all atomic masses

Question 5

What is the standard isotope needed to base all atomic masses?

Answer 5

carbon-12 isotope, which is the standard isotope for the measurement of atomic masses

Question 6

What does one atom of carbon-12 have the mass of?

Answer 6

1.92646538 x 10^-26kg

Question 7

Instead of working in kg, what is the alternative unit called?

Answer 7

atomic mass unit (u)

Question 8

What is the mass of carbon-12 isotope defined as?

Answer 8

12 atomic mass units (12u)

Question 9

What is the standard mass for atomic mass?

Answer 9

1 u

Question 10

Essentially, what is 1u the approximate mass of?

Answer 10

a proton or a neutron

Question 11

What is relative isotopic mass?

Answer 11

the mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

Question 12

Why does relative isotopic mass have no units?

Answer 12

because it is a ratio of two masses