Unit 2 Test

What did Rutherford discover about atoms?

• An atom is always negatively charged.

• An atom is mostly empty space, but has a dense positively charged center(nucleus).

• An atom is always positively charged.

• All particles will pass straight through gold foil with no change in path.

This model this model was the first to show a nucleus, consisting of protons and neutron.  Electrons surround the nucleus but are not shown in distinct energy levels. 

• The "Nuclear Model" by Rutherford

• The "Plum Pudding Model" of the atom by Thomson

• The "Quantum Mechanical Modell" of the atom by Heisenberg

• Democritus's model of the atom

An atom has a full first energy level and 7 electrons in its second level. How many electrons does this atom have?

• 2

• 7

• 9

• Need more information

Which THREE postulates of Dalton's atomic theory have been proven false by later research? Be sure to select three (3) answer choices for this question.

• All matter is made up of atoms

• Atoms are indivisible and indestructible

• Atoms of different elements have different masses

• All atoms of the same element have identical properties

• Atoms combine in fixed, whole-number ratios to form compounds

Which element in period 4 has the highest electronegativity?

• potassium

• calcium

• copper

• bromine

He, Ne, and Ar are all noble gases (Group 18). What is common among these gases?

• They are flammable.

• They are highly reactive.

• They are metals.

• They are unreactive.

Most of the elements on the periodic table are classified as _____.

• Metals

• Nonmetals

• Metalloids

• Periods

A(n) _______ is the smallest particle of an element that has the chemical properties of that element.

• electron

• compound

• atom

• molecule

Below is a square that represents one element of the periodic table.

What information is in this square of the periodic table, from top to bottom?

• average atomic mass, chemical symbol, chemical name, atomic number

• atomic number, chemical symbol, chemical name, average atomic mass

• average atomic mass, chemical symbol, chemical name, proton number

• atomic number, chemical symbol, chemical name, proton number

As you move down a group, atomic radius increases because - 

• you add more and more neutrons
• you add more and more protons
• you add more and more shells (energy levels)
• you add more atomic mass