Y2 Unit 5 Written Work#1

Which atomic model was the first one to include electrons?

• Dalton's Snooker Ball model

• Thomson's Plum Pudding model

• Rutherford's Electron Cloud model

• Bohr's Electron Shell model

Which atomic model was the first one to include the nucleus?

• Dalton's Snooker Ball Model

• Thomson's Plum Pudding model

• Rutherford's Electron Cloud model

• Bohr's Electron Shell Model

He confirmed the existence of uncharged particles in the nucleus called neutrons.

• JJ Thompson

• Ernest Rutherford

• John Dalton

• James Chadwick

Why is the area around the nucleus in the modern atomic model called the electron cloud?

• because it contains a dense cloud of many electrons

• because the electrons are constantly moving in unpredictable ways around the nucleus

• because scientists do not know how many electrons an atom has

• because electrons are large and spread out

During a science experiment, Kharis and Khesed are comparing two forms of sodium. How do these two forms of sodium differ?

• in the number of nuclei
  

• in the number of electrons

• in the number of protons

• in the number of neutrons

Noah is studying the properties of elements in his chemistry class. He learns that a Gold atom has 79 protons, 118 neutrons, and 79 electrons. What is the mass of this atom? Show solution.

Jimmy is conducting an experiment on building an atom with the following components:

Protons: 7
Neutrons: 6
Electrons: 6

What element did he form?

During an archaeological dig, Dr. X uncovers a sealed container with a radioactive symbol and the nuclide symbol shown on the left. To assess the safety of the find, determine the number of protons, electrons, and neutrons in the isotope.

(# of protons, # of electrons, # of neutrons)

During a virtual experiment, Lily is trying to understand how to change a neutral atom into an anion. What can she add to achieve this?

Imagine Arjun and Ava are discussing atoms in their science class. They wonder what has to be true about protons and electrons in all neutral atoms. Can you explain this to them?