Checkpoint 1-2

Which atomic model proposed that atoms were indivisible, indestructible spheres?

• Dalton's model
• Thomson's model
• Rutherford's model
• Bohr's model

What did Rutherford's gold foil experiment reveal about the structure of the atom?

• Atoms were mostly empty space
• Atoms were solid spheres
• Electrons were negatively charged
• Protons were positively charged

Which subatomic particle has a relative charge of +1?

• Proton
• Neutron
• Electron
• Positron

What is the relative mass of an electron?

• 10
• 1
• 1836
• 0

What does the atomic number of an element represent?

• Number of protons
• Number of neutrons
• Mass of the atoms
• Total number of particles

Isotopes of an element have the same number of:

• Protons
• Neutrons
• Electrons
• Nucleons

What does the mass number of an atom represent?

• Number of protons
• Number of neutrons
• Number of electrons
• Sum of protons and neutrons

An element has a mass number of 40 and 22 neutrons. How many protons does it have?

• 18
• 22
• 40
• 62