Isotopes Lesson

Isotopes Lesson

by Andrew Baldwin

​Objectives

​Students will be able to explain how the atomic structure of isotopes are similar and different from one another.

Multiple Choice

Niels Bohr added _______________ to the model of the atom.

• electrons.

• a nucleus.

• neutrons.

• energy levels.

Multiple Choice

Which of the following is the best description of J.J. Thomson's model of the atom?

• a featureless, indivisible sphere

• a sphere of positive material with electrons embedded in it

• mostly empty space with electrons randomly orbiting around a positive nucleus

• mostly empty space with electrons located in set orbits around a positive nucleus.

Multiple Choice

Who proposed the following model for the atom?

"Atoms are solid spheres. Each element is made of a different type of atom."

• Bohr

• Chadwick

• Dalton

• Rutherford

Multiple Choice

How many protons are in a Chlorine atom? (Mass number = 35)

• 17

• 35

• 35.45

• 18

Multiple Choice

How many neutrons are in a Phosphorus atom? (Mass Number = 31)

• 15

• 30.9738

• 16

• 31

​Reading the Symbol

• ​Note: This is not reflective of the Periodic table Organization.

• ​Mass Number provided at the top and atomic number sometimes at the bottom.

  • ​The only change should be the top number.

​Anything else?

• ​Sometimes it is given in Hyphen notation.

  • ​Element symbol or name hyphen (dash) Mass Number.

Multiple Choice

In a correctly written symbol what would be located in the "A" position?

• number of neutrons

• atomic number

• number of electrons 

• mass number

Multiple Choice

What quantities vary between isotopes of an element?

• protons, electrons, and atomic mass

• protons, electrons, and atomic number

• neutrons and electrons

• neutrons and atomic mass

Multiple Choice

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

Multiple Choice

How many protons does this isotope of titanium have?

• 48

• 22

• 26

• 70

Multiple Choice

Isotopes are atoms of the same element with different #’s of __________ & therefore different __________.

• n⁰ ;  atomic #’s

• p⁺ ; atomic #’s

• e^- ; atomic masses

• n⁰ ; atomic masses

Multiple Choice

If X is the symbol for an element, which of the following two symbols represent isotopes of the same element?  

• I and II

• III and IV

• I and IV

• I and III

​Time for Practice

​Back to Canvas and Complete Counting Particles Level 2