What is all matter made up of?

• Atoms of various elements

• Molecules

• Compounds

• Mixtures

Tags

NGSS.MS-PS1-1

What does the periodic table help us understand about each element?

• The number of protons and neutrons in an atom

• The atomic mass of the element

• The chemical symbol of the element

• The electron configuration of the element

What is the periodic table used for?

(Select all that are true.)

• to find out how many protons an element has

• to find the names of the elements

• to eat dinner off of in bed

• to find out how many neutrons an element has

What does the atomic number of an element represent?

• The number of protons in the nucleus

• The number of neutrons in the nucleus

• The average mass of the element

• The atomic symbol of the element

How can you calculate the approximate number of neutrons in a carbon atom?

• Subtract the atomic number from the rounded standard atomic weight

• Add the atomic number to the standard atomic weight

• Multiply the atomic number by the standard atomic weight

• Divide the standard atomic weight by the atomic number

What is the atomic symbol for carbon?

• C

• Ca

• Cb

• Cr

Label the symbols on this periodic table entry.

a

b

c

d

Atomic Number

Atomic Symbol

Name

Atomic Weight

Answer explanation

For the element fluorine, F is the atomic symbol. The atomic number of fluorine is 9. The standard atomic weight is 18.9984.

Select the element with 18 protons in its nucleus and the element with 7 protons in its nucleus.

Answer explanation

Argon, or Ar, has an atomic number of 18. This means that argon has 18 protons in its nucleus.

Tags

NGSS.MS-PS1-1

Select the element with approximately 22 neutrons in its nucleus.

(Hint: Round the atomic weight to the nearest whole number.)

• Ar

• As

• N

• Ne

• S

Answer explanation

Subtracting the atomic number from the rounded standard atomic weight gives an approximate number of neutrons in an atom of that element. To approximate the number of neutrons in argon, round its standard atomic weight to 40 and subtract its atomic number:

Tags

NGSS.MS-PS1-1

Which element has the atomic symbol (K)?

• 
  beryllium

• sodium

• calcium

• magnesium

• potassium

Answer explanation

K stands for potassium. Some elements have symbols that relate to their names in English, such as O for oxygen. However, many elements have atomic symbols that relate to their names in Latin. Potassium in Latin is kalium.