Isotopes and Atomic Mass

In order for two elements to be isotopes, what must be DIFFERENT?

• Protons

• Electrons

• Neutrons

• Neutrons & Mass

Calculate the atomic mass of silicon. The three silicon isotopes have atomic masses and relative abundances of 27.9 amu (92.2%), 28.9 amu (4.7%) and 29.9 amu (3.1%). Round your answer to 3 sig figs and only type a #.

Calculate the average atomic mass of the following element:

²⁵Y (11%), ³²Y (39%), ²⁹Y (22%), ³⁰Y (28%)

• 32.0

• 30.0

• 29.0

What mass would the following atom have?

9 protons, 10 electrons, and 11 neutrons

• 30 amu

• 19 amu

• 20 amu

• 21 amu

Tags

NGSS.MS-PS1-1

What do the mass numbers on the periodic table represent?

• The mass of the most abundant isotope

• The mass of the least abundant isotope

• The average mass of the two most abundant isotopes

• The average mass of all the isotopes

Copper is made of two isotopes. The mass and abundances are 62.9 amu (69.2%) and 64.9 amu (30.9%). What is the weighted average mass of these two isotopes? Round your answer to 3 sig figs and only type a #

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

How many neutrons does the isotope of lithium have?

• 8
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

How many protons does this isotope of titanium have?

• 48
• 22
• 26
• 70

Tags

NGSS.MS-PS1-1

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

• number of neutrons
• atomic number
• number of electrons 
• mass number

Tags

NGSS.MS-PS1-1