What did Democritus, Dalton, Thomson, Rutherford, and Bohr all have in common?

• They were all cool dudes.
• They each identified new isotopes of atoms.
• They each contributed to the development of the atomic theory.
• They each designed a new building.

all matter is made of what 

• energy 
• atoms 
• electrons 
• compounds 

Tags

NGSS.MS-PS1-1

The positive particles of an atom are 

• electrons 
• positrons 
• neutrons 
• protons 

the central region of an atom where its neutrons and protons are is its 

• nucleus 
• electron cloud
• core 
• center 

Tags

NGSS.MS-PS1-1

an atom with atomic number 6 would have how many protons 

• 6
• 12
• 3
• cannot be determined 

Particles in an atom that are neutral and have no charge are 

• negatrons 
• electrons 
• neutrons 
• protons 

True or False? Neutrons have a negative charge

• True
• False

What is the atomic number for an element with three protons?

• 2
• 1
• 3
• 6

The subatomic particle with a negative charge is the

• electron
• proton
• neutron
• nucleus 

What is the mass number?

• the number of protons
• the number of protons and neutrons
• the number of neutrons
• the number of protons and electrons