Isotopes Ion and Average Atomic Mass

How many neutrons are in an atom of carbon-14?

• 6

• 8

• 10

• 14

How many protons does this isotope of titanium have?

• 22

• 26

• 48

• 70

How many electrons are in an atom that has an atomic number of 34, an atomic mass of 74 and a charge of -2?

• 2

• 34

• 36

• 40

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Write the hyphen notation for the isotope that has 39 protons and 50 neutrons.

• Yttrium-11

• Tin-39

• Tin-89

• Yttrium-89

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

Tags

NGSS.HS-PS1-8

Chromium has four naturally occurring isotopes (chromium-50, chromium-52, chromium-53, and chromium-54). What is the average atomic mass of Chromium?

• 4

• 51.996

• 52.25

• Not enough information was given.

Tags

NGSS.HS-PS1-8

An element has three isotopes. Given the abundances and relative masses, calculate the average atomic mass and determine (from the periodic table) which element it is.

Abundances | Relative masses

0.005% | 234.04 amu

0.720% | 235.04 amu

99.275% | 238.05 amu

• Uranium (#92, Atomic Mass: 238.03 amu)

• Fluorine (#9, Atomic Mass: 19.00 amu)

• Mercury (#89, Atomic Mass: 200.59 amu)

• Polonium (#84 209 amu)

Four isotopes of lead include lead-204, lead-206, lead-207, and lead-208.  The average atomic mass of lead is 207.2.  Which isotope of lead is likely to be the most abundant.

• 204
• 206
• 207
• 208

Rubidium has two naturally occurring isotopes, ⁸⁵Rb (relative mass 84.9118 amu) and ⁸⁷Rb (relative mass 86.9092 amu). The abundance of ⁸⁷Rb is 27.8%, If rubidium has an average atomic mass of 85.47 amu, what is the % abundance of ⁸⁵Rb (in percent)?

• 27.9%

• 72.1%

• 74.63%

• 34.29%

What is the name of the pictured isotope?

• Carbon-12
• Carbon-13
• Carbon-14
• Carbon-15

Tags

NGSS.HS-PS1-8