Atomic structure and Isotopes

The positive particles of an atom are 

• electrons 
• positrons 
• neutrons 
• protons 

True or False? Neutrons have a negative charge

• True
• False

How many neutrons in C-14?

• 6
• 7
• 14
• 8

Tags

NGSS.HS-PS1-8

What is an isotope?

• A charged atom

• Two atoms of the same element with different amounts of neutrons

• Two atoms of the same element with different amounts of protons

• A neutral atom

Tags

NGSS.HS-PS1-8

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

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-PS1-8

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

Tags

NGSS.MS-PS1-1

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

Tags

NGSS.MS-PS1-1