Protons, neutrons and electrons
Grade 8 Science Worksheet
Circle the best answer, or write your answer on the line.
A potassium atom has atomic number 19 and mass number 39. How many neutrons does it have, Ari?
A zinc atom has atomic number 30 and mass number 64. How many neutrons does it have, Bo?
A silver atom has atomic number 47 and mass number 107. How many neutrons does it have, Esme?
Read this first
Table (IUPAC data)
Atomic number, symbol, name. 6 C carbon; 7 N nitrogen; 8 O oxygen; 9 F fluorine; 13 Al aluminum; 16 S sulfur.
An atom has 8 protons and 8 neutrons. Using the table, which element is it, Jun?
- You can't tell without the electrons
- Sulfur, element 16
- It depends on the neutrons
- Oxygen
Atomic number, symbol, name. 5 B boron; 6 C carbon; 7 N nitrogen; 8 O oxygen; 13 Al aluminum. An atom has 6 protons and 7 neutrons. Using the table, which element is it, Luz?
- Aluminum, element 13
- Carbon
- Oxygen
- Nitrogen, from the 7 neutrons
Where is almost all of an atom's mass, Milo?
- In the nucleus
- Shared evenly among its particles
- In the empty space
- In the electrons, since they fill the atom
How does an electron's mass compare with a proton's, Noah?
- Exactly zero
- About the same
- Much smaller: about 1/1836 as much
- About twice as much
Which two particles have about the same mass, Pia?
- A neutron and an electron
- Each of the three
- A proton and an electron
- A proton and a neutron
a nucleus with 3 protons (marked +) and 4 neutrons (no mark), and 3 electrons (marked −) around it. Ren counts the particles in the lithium atom drawing. What is its mass number?
- Mass number 7
- Mass number 10
- Mass number 4
- Mass number 3
Zee counts the particles in the nitrogen atom drawing. What is its mass number?
- Mass number 21
- Mass number 14
- Mass number 7
- Mass number 28