4.2 Defining the Atom ม5

What is the smallest "building block" of the elements that make up the universe?

• an atom
• an electron
• a proton
• a cell

What sub-atomic particle has neither a positive nor a negative charge?

• proton

• neutron

• electron

• nucleus

Who discovered the electron?

• Rutherford

• Thomson

• Milikan

• Dalton

What is an atom mostly made up of?

• protons
• electrons
• empty space
• neutrons

Tags

NGSS.MS-PS1-1

This is a model of what was thought be an atom - what is the model called?

• Cathode Ray Tube Experiment

• Gold Foil Experiment

• Plum Pudding Model

• Planetary Model

Ernest Rutherford discovered that the atom was mostly _________________ and has a _______________ charged nucleus.

• empty space, positively
• empty space, negatively
• full of protons, positively
• full of neutrons, negatively

This is a model of what was thought be an atom after what experiment?

• Cathode Ray Tube Experiment
• Gold Foil Experiment
• Plum Pudding Model
• Planetary Model

Millikan was able to calculate the charge on an electron & using the charge-to-mass ratio he calculated the mass. What measurements did he calculate?

• 1.6 x 10^-19 C / 9.1 x 10^-28 g

• 9.1 x 10^-28 C / 1.6 x 10^-19 kg

• 9.1 x 10^-19 C / 1.6 x 10^-28 g

• 1.6 x 10^-28 C / 9.1 x 10^-19 g

Imagine an atom which has had all of its electrons removed. What charge will the atom have?

• All atoms are neutral

• Negative charge

• Positive charge

• No charge

How do electrons remain suspended in the cloud surrounding the nucleus?

• Reverse gravity prevent them from escaping

• The outer shell of the cloud retains the electrons in situ

• Electrstatic charges from other atoms repels the electrons

• The negatively charged electrons are attracted to the positively charged nucleus