WorksheetsATOM
Total questions: 7
Worksheet time: 4mins
Which of the following statements is NOT TRUE about Democritus atomic theory?
solid
indestructible
collides with each other
smaller particles are charged.
Which statement is true according to Dalton's theory?
Atoms of different elements can join to form larger atoms.
Atoms can be subdivided into smaller particles.
Atoms of the same element differ in electric charge.
Atoms of the same element are exactly alike.
An atom has 25 protons and 30 neutrons. How many electrons are needed to make the atom neutral?
0
25
30
35
In 1904 JJ Thompson discovered that atoms actually contained particles called electrons. Which of these best describes an electron?
Much much smaller than the other particles, positively-charged
Much much smaller than the other particles, negatively-charged
Make up most of the mass of the atom, negatively-charged
Contain most of the mass of the atom, no charge
When 24.3 g magnesium reacts completely with 16.0 g oxygen, exactly 40.3 g magnesium oxide is formed. Which of the following law is illustrated by this observation?
Law of Definite Proportion
Law of Conservation of Mass
Law of Multiple proportion
How did each model of the atom helped to develop the atomic theory?
Each model provided opinions that were added.
Each model showed different properties of the same structure.
Each model showed new particles that had been discovered.
Each model contributed the other to modify and update the theory.
Group Name and Number for Magnesium
Alkaline Earth Metals 2 or 2A
Noble Gases 18 or 8A
Halogens 17 or 7A
Alkali Metals 1 or 1A
