Unit 2.05 Quiz Semester 1

The isotope of an atom containing 40 protons and 51 neutrons suddenly has two neutrons added to it. What isotope is created?

• Antimony-53

• Zirconium-53

• Zirconium-93

• Antimony-93

The isotope of an atom containing 31 protons and 39 neutrons suddenly has two neutrons added to it. What isotope is created?

• Yttrium-41

• Gallium-72

• Gallium-41

• Yttrium-72

A neutral atom possesses an atomic number of 15 and an atomic mass of 31. Three electrons are gained. What is the result of this conversion?

• a positively charged ion

• a negatively charged ion

• a new isotope

• a new isomer of the element

A neutral atom possesses an atomic number of 13 and an atomic mass of 27. Three electrons are lost. From what region of the atom are they lost?

• outside the atom outside

• the nucleus inside

• the nucleus both inside and

• outside the nucleus

What does an atomic number represent in an atom?

• number of electrons

• number of protons

• number of protons and neutrons

• number of neutrons

How are the number of protons represented in the periodic table?

• atomic number

• atomic mass

• number isotope

• mass number

Radioactive isotopes of an atom are

• more scarce.

• more abundant.

• less stable.

• more stable.

What differs between a radioactive isotope and a stable isotope?

• Radioactive isotopes last for less time.

• Radioactive isotopes last longer.

• There is no difference.

• Stable isotopes are shorter.

Which statement is true about the atomic mass?

• It is never greater than the atomic number.

• It always equals the atomic number.

• It is always lower than the atomic number.

• it can be greater than the atomic number

How do the atomic mass and atomic number compare for helium?

• The atomic number is greater.

• The atomic mass is greater.

• The atomic mass and atomic number are equal.

• Helium does not have an atomic number.