Chapter 4 Assessment

According to Dalton's atomic theory, which of the following are FALSE?

• Atoms of an element are identical to atoms of other elements.

• Every element is made of atoms.

• Atoms of different elements combine to form compounds.

• In a chemical reaction, some atoms disappear and new atoms appear.

Match the subatomic particles to each of the descriptions below:

• mass number - atomic number

• Neutrons

• negative charge

• Atomic mass

• Weighted average of all isotopes

• Electrons

• positive charge

  atomic number

• 1. Protons

Which of the following isotopes have the same number of protons?

• a

• b

• c

• d

Which of the following isotopes have the same mass number?

• a

• b

• c

• d

Identify the letters in the image.

a

b

c

Element Symbol

Neutron number

Mass number

Atomic number

The atomic number gives the number of ___ in the nucleus.

In a neutral atom, the number of electrons is equal to the number of ____.

The number of protons and neutrons in an atom is the ___ number.

Match the Chemical Symbol to the correct group or period number:

• Group 14

• Hydrogen

• Period 1

• Sodium

• Period 3

• Bromine

• Group 17

• Argon

• Group 18

• Carbon

Elements that are shiny and conduct heat are called

• Nonmetals.

• metals.

• metalloids.

• Noble gases.