Atom and Element

What is the particle labeled in III?

• Proton

• Neutron

• Electron

• Nucleus

Tags

NGSS.MS-PS1-1

An element has an atomic number of 8.

How many neutrons are present if the mass number is 16?

(a)  

Tags

NGSS.MS-PS1-1

Why is the atomic number used to identify the identity of an element instead of the atomic mass?

• Atomic mass is always the same for all elements while atomic number is different for all elements.

• The atomic number is less stable than atomic mass.
• Atomic mass is used to determine the chemical properties of an element while atomic number identifies the number of protons.

• The atomic number is used to identify an element because it uniquely defines the element, while atomic mass can vary among isotopes.

What is the atomic number of this atom?

• 2
• 4
• 5

• 6

Tags

NGSS.MS-PS1-1

How many protons are in Beryllium?

• 4
• 9
• 5
• 2

Tags

NGSS.MS-PS1-1

What is an atomic number?

• The number of protons in an element
• The number of neutrons in an element
• The number of protons and neutrons.
• The number of protons and electrons.

Tags

NGSS.MS-PS1-1

What is the atomic number of this atom?

• 8
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

How many neutrons are there for this atom?

• 8
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

How many electrons are there for this atom?

• 8
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

What is the electrical charge of an atom at ground state?

• Always negative
• Always positive
• Varies with temperature
• Zero