Ontario Grade 9 Science Class Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Master Grade 9 Science with our comprehensive practice exam. Test your knowledge, identify weak areas, and boost your confidence for academic success.

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Define a molecule.

An object with more protons than electrons
A neutral particle within an atom's nucleus
Two or more atoms of the same or different elements chemically joined together
An element that conducts electricity but not heat

The correct answer is: Two or more atoms of the same or different elements chemically joined together

A is incorrect because having more protons than electrons does not define a molecule. A molecule can have an equal number of protons and electrons, such as in the case of a neutral molecule. B is incorrect because a molecule is not a particle within an atom's nucleus. A molecule is made up of atoms, which make up the nucleus along with neutrons. D is incorrect because being able to conduct electricity has nothing to do with defining a molecule. A molecule can conduct electricity if it has charged particles, but that is not a defining characteristic. A molecule can also be non-conductive.