Module 3: Atomic Theory and Isotopes

Which of the following is not a particle of atom?

• Proton

• Electron

• Positron

• Neutron

The nucleus of an atom has

• Proton and electron

• Proton and neutron

• Electron and neutron

• Proton only

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Mass number is the total number of

• Protons, electrons and neutrons

• Protons and electrons

• Protons and neutrons

• Electrons and neutrons

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The mass number of an element is 31 and the atomic number is 15. How many electrons does it have?

• 14

• 15

• 16

• 31

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NGSS.HS-PS1-1

The mass number of an element is 31 and the atomic number is 15. How many neutrons does it have?

• 15

• 14

• 16

• 31

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NGSS.MS-PS1-1

A neutral atom of an element has 19 electrons and 20 neutrons. What is its atomic number?

• 39

• 19

• 20

• 1

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Isotopes have same atomic number but different

• number of protons

• number of electrons

• number of neutrons

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The dense central region of an atom where its neutrons and protons are is its

• nucleus

• electron cloud

• core

• center

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How many protons does this isotope of titanium have?

• 48
• 22
• 26
• 70

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NGSS.HS-PS1-8

How many neutrons does the isotope of lithium have?

• 8
• 3
• 4
• 5

Tags

NGSS.HS-PS1-8