What is ionization energy?

• energy required to remove a neutron

• energy needed to add an electron to an atom

• Energy required to remove an electron from an atom

• Energy required to remove a proton from an atom.

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NGSS.HS-PS1-1

• 6

• 8

• 10

• 7

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

How many valence electrons are in Chlorine?

• 5

• 4

• 6

• 7

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which symbol correctly represents an element with 20 protons and 25 neutrons?

• D - 25

• D - 45

• D-20

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NGSS.MS-PS1-1

How much time will be required for a sample of H-3 to lose 75% of its radioactivity? The half-life of tritium is 12.26 years

• 24.52 years

• 35.5 years

• 40.2 years

• 36.4 years

Answer explanation

If it loses 75% of its radioactivity, then 25% remains. For H-3 to have 25% remain, it would take 2 half lives. 2 * 12. 26 years = 24.52

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NGSS.HS-PS1-8

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

• 24.2 g

• 7.2 g

• 12.5 g

• 50 g

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NGSS.HS-PS1-8

What are the 3 subatomic particles that make-up the atom?

• protons, neutrons, and isotopes
• neutrons, isotopes, and electrons
• positives, negatives, and electrons
• protons, neutrons, and electrons

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NGSS.MS-PS1-1

The negatively charged particles of an atom are the ______.

• electrons
• protons
• neutrons
• protons & neutrons

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NGSS.MS-PS1-1

What number indicates the nucleus?

• 1
• 2
• 3
• 4

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NGSS.HS-PS1-8

Proposed that electrons move around the nucleus in specific layers, or shells.

• Bohr

• Rutherford

• Chadwick

• Thomson

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NGSS.HS-PS1-1