Isotopes

Which of the following are isotopes?

a) ¹⁴ ₇X b) ¹⁴ ₆X c) ¹⁵ ₇X d) ¹⁵ ₈X

• a) and b)

• a) and c)

• c) and d)

• a) and d)

If X is the symbol for an element, which of the following two symbols represent    isotopes of the same element?     I. ⁷⁷₃₅X  II. ⁷⁷₃₃X  III. ⁸¹₃₇X  IV. ⁸¹₃₅ X

• I and II
• III and IV
• I and IV
• I and III

How is carbon-12 different from carbon-14?

• They have a different number of protons

• they have a different number of electrons

• they have a different number of neutrons

• they have a different mass number

What do carbon-12 and carbon-14 have in common?

• they have same number of protons
• they have the same number of neutrons
• they have the same atomic mass
• they have the same atomic weight

What can you conclude about carbon-14 from its name?

• It has 14 electrons

• it has 14 neutrons

• it has 14 protons

• it has a mass number of 14

What do these isotopes of carbon all have in common?

• neutrons & mass number
• atomic number and neutrons
• atomic number and electrons
• protons, atomic number, and mass number

Isotopes are atoms of the same element with different __________, therefore they have different __________.

• neutrons ; atomic numbers

• protons ; atomic numbers

• electrons ; mass numbers

• neutrons ; mass number

Two isotopes of carbon are carbon-12 and carbon-14.  These isotopes differ from one another by two protons.

• true
• false

Atoms of the same element which have a different number of neutrons are called _________________.

• ions

• isotopes

• quarks

• molecules

If a proton is added or removed from an atom, what happens?

• It becomes a different element.

• It becomes a different isotope.

• Nothing happens.

• It becomes a different atom.