Ions & Isotopes

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

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.

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)

Tags

NGSS.HS-PS1-7

NGSS.HS-PS1-8

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%

Tags

NGSS.HS-PS1-7

What is the name of the pictured isotope?

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