# Worksheet: Up Quarks and Down Quarks

Q1:

How many quarks are there in a neutron?

Q2:

What is the relative charge of a down quark?

• A
• B
• C
• D
• E1

Q3:

How many quarks are there in a proton?

Q4:

The nucleus of a carbon-14 atom contains 6 protons and 8 neutrons.

How many up quarks are in the nucleus in total?

How many down quarks are in the nucleus in total?

Q5:

 Quark Up Down Relative Charge 2 3 − 1 3

The table shows the relative charges of the up and down quarks. If a composite particle were made up of 3 up quarks, what would the relative charge of that composite particle be?

• A
• B+1
• C
• D+2
• E+3

Q6:

What is the relative charge of an up quark?

• A
• B
• C
• D
• E1

Q7:

Quark Relative Charge Relative Mass
Up
Down

A group of physicists detect a particle that has a relative charge of and a mass times the mass of a proton. Which of the following composite particles, made of up and down quarks, could the mysterious particle be?

• AUp, down, down
• BUp, up, up
• CUp, up, up, up, down
• DThe particle cannot be any of these combinations.
• EUp, up, up, down, down

Q8:

The diagram shows 4 composite particles. Each particle is made up of 3 quarks. Quarks with the letter u are up quarks, and quarks with the letter d are down quarks. Red particles are particles with a positive electric charge, and blue particles are particles with a negative electric charge.

Which of the 4 composite particles is a proton?

• A(c)
• B(a)
• C(d)
• D(b)
• ENone

Which of the 4 composite particles is a neutron?

• A(c)
• B(d)
• C(b)
• D(a)
• ENone

Q9:

The nucleus of a helium-4 atom contains 2 protons and 2 neutrons.

How many up quarks are in the nucleus in total?

How many down quarks are in the nucleus in total?

Q10:

 Quark Up Down Relative Charge 2 3 − 1 3

The table shows the relative charges of the up and down quarks. If a composite particle were made up of 3 down quarks, what would the relative charge of that composite particle be?

• A
• B
• C
• D
• E

Q11:

Which of the following is the correct symbol for an up quark?

• A
• B
• C
• D
• E

Q12:

Which of the following is the correct symbol for a down quark?

• A
• B
• C
• D
• E