Elements, Compounds and Mixtures

Single substance is a substance composed of a single material, for example, water, chalk, iron metal and copper wire, salt, sugar, 24-karat gold, oxygen, hydrogen, and so on. The first part of a single substance is an element. An element is a single substance that cannot be further broken down into smaller and simpler substances. Examples in everyday life are 24-karat gold and pure nitrogen gas. A chemical compound is a single substance composed of many elements combined into one. A compound is a combination of various elements with specific ratios. Example: water vapor (H2O). A mixture is a combination of various elements with an indefinite ratio, for example: sugar solution.

Take a look at the following atomic model diagram! Which one is compound?

• A. (1), (4), and (6)

• B. (2), (3), and (4)

• C. (2), (3), and (5)

• D. (3), (5), and (6)

The name of the element in the picture is..

• A. Ferrum

• B. Hydrargyrum

• C. Carbon

• D. Aurum

Take a look at the names of several substances

(1) Air

(2) Iron

(3) Seawater

(4) Pure water

(5) Gold

Among the following substances, the one that is a mixture is …

• A. 1 and 3

• B. 2 and 4

• C. 4 and 5

• D. 1 and 2

Lala and Lula are conducting an experiment together in the laboratory. Lala puts one spoon of sugar into a glass of water and stirs it, then labels the glass as (X). Lula puts one spoon of sand into a glass of water and stirs it, then labels it as (Y).

They observe both experiments. From the discussion, the correct conclusion of the experiment is...

• A. Label X and Y are homogeneous mixtures

• B. Label X and Y are heterogenous mixtures

• C. Label X is a homogeneous mixture and label Y is a heterogeneous mixture

• D.Label X is a heterogeneous mixture and label Y is a homogeneous mixture

Milk packaged belongs to the category of...

• A. Elements

• B. Compounds

• C. Mixtures

• D. Atoms

The following element that is not represented by single letter is...

• A. Gold

• B. Hydrogen

• C. Oxygen

• D. Carbon

The following is a heterogeneous mixture...

• A. Air, cement mixture and syrup

• B. Mixed ice, alloy (metal mixture) and tea water

• C. Alloy (metal mixture), syrup and sugar solution

• D. Oil in water, compote and cement mixture

The correct number of each atom in the compound Calcium Carbonat (CaCO3) is...

• A. Calcium=1, Carbon=1, Oxygen=3

• B. Calcium=2, Carbon=1, Oxygen=3

• C. Calcium=1, Carbon=2, Oxygen=3

• D. Calcium=2, Carbon=2, Oxygen=1

A mixture is separated using equipment as shown in the picture below!

The mixture that is properly separated using equipment as shown in the picture is...

• A. Mixture of water and oil

• B. Mixture of iron powder and sulfur powder

• C. Saltwater

• D. Mixture of water and sand

The most correct opinion of the students is...

• A. Celine

• B. Felix

• C. Monique

• D. Ryan