Atoms, Elements, Molecules, and Compounds Explained

The video tutorial introduces the concepts of matter, elements, molecules, and compounds. It explains that matter is anything with mass and volume, and it is made up of elements, which are distinct types of matter with only one type of atom. The periodic table lists 118 elements. Molecules are formed when atoms bond together, and compounds are made of different types of atoms in a fixed ratio. The video provides examples of elements and compounds, such as water (H2O) and carbon dioxide (CO2), and discusses their properties and how they differ from their constituent elements.

What is the defining characteristic of an element?

• It can be broken down into simpler substances.

• It consists of only one type of atom.

• It is always a solid.

• It has a fixed volume.

How many elements are listed in the periodic table?

• 128

• 108

• 100

• 118

What is the chemical formula for a molecule of oxygen?

• O2

• H2O

• O3

• O

Which of the following is a compound?

• Water

• Hydrogen

• Gold

• Oxygen

What happens to the properties of a compound when it is broken down into its elements?

• The properties change to those of the individual elements.

• The compound becomes a mixture.

• The compound becomes an element.

• The properties remain the same.

Which of the following is true about elements?

• They have the same type of atom.

• They are always found in nature as compounds.

• They can be broken down into simpler substances.

• They have more than one type of atom.

What is the formula for nitrogen dioxide?

• NO

• NO2

• N2O

• N2O4

Which of the following is an example of a compound?

• Neon

• Iron

• Sodium chloride

• Helium

What is the smallest unit of matter that retains the properties of an element?

• Atom

• Molecule

• Compound

• Mixture

Which of the following statements is true about compounds?

• They have a fixed ratio of different atoms.

• They can be separated into elements by physical means.

• They consist of only one type of atom.

• They are always gases.