Worksheet No. 1-Atoms and Molecules

Which of the following describes an atom?

• It is the smallest particle of an element that can exist.

• Atoms are the building blocks of all matter.

• Atoms are made up of three sub-atomic particles, namely protons, neutrons and electrons.

• All of them

In modern atomic model, electrons are found in the ____________.

• orbit

• nucleus

• electron cloud

• all of the given choices

What are the sub-atomic particles makes the nucleus of an atom?

• protons and electrons

• electrons and neutrons

• neutrons and protons

• neutrons, protons and electrons

He believed that nothing could be smaller than an atom and was known as the Father of Atomic Theory.

TEM is a powerful microscope that allows us to see atoms. TEM stands for ______________________.

• Transportation Electron Microscope

• Transmission Electron Microscope

• Transfer Electron Microscope

• Trapper Electron Microscope

Representation of atoms using models and diagrams makes the study and understanding of atoms and molecules easier.

• True

• False

Transmission Electron Microscope (TEM) was invented by Ernst Ruska in what year?

• 1911

• 1921

• 1931

• 1941

Tick the differences between an atom and a molecule.

• Atom can’t be subdivided into individual atoms while molecule can be subdivided into individual atoms.

• Atoms are not bonded while molecules are atoms that are bonded.

• An atom is not stable by itself while a molecule is usually stable to exist by itself.

• An atom consists of protons, neutrons and electrons while a molecule is a combination of atoms.

They are made up of two or more atoms of the same kind or of different kinds chemically combined together.

A molecule in an element is made up of two or more atoms of the different kind chemically combined together.

• True

• False