GRADE 8 Science – Elements and compounds Quiz

An element is a pure substance made of only one type of atom, it cannot be broken down into simpler substances by ordinary chemical means.

Oxygen is an example of an element as it is made up of only oxygen atoms and cannot be broken down into simpler substances.

A compound is a substance made of two or more elements chemically combined in a fixed ratio.

Carbon Dioxide is an example of a compound as it is made up of carbon and oxygen chemically bonded together.

Compounds can be separated into their individual elements through chemical reactions, where the bonds holding the elements together are broken.

Elements cannot be separated into different substances by physical means because they are composed of only one type of atom.

Water's chemical formula is H2O, which indicates that it is made up of two hydrogen atoms and one oxygen atom chemically bonded together.

Carbon Dioxide is typically found in the gaseous state at room temperature and pressure.

The properties of a compound remain the same when its elements are chemically separated, as it is the chemical composition that determines the properties.

Sodium Chloride (NaCl) is a compound made of sodium and chlorine atoms chemically bonded together in a fixed ratio.

Oxygen is an example of an element because it cannot be broken down into simpler substances by chemical reactions. Sugar, salt, and water are compounds made up of different elements.

A compound is made up of two or more elements that are chemically bonded together. It has a fixed ratio of elements in its composition.

Diamond is an example of an element as it is composed of a single type of atom, carbon. It cannot be broken down into simpler substances.

Sodium Chloride (table salt) is a compound made up of sodium and chlorine elements chemically bonded together. Iron, gold, and air are not compounds.

The primary difference between an element and a compound is that elements can be broken down into simpler substances by chemical reactions, while compounds cannot be broken down into simpler substances.

Air is a mixture of different gases such as oxygen, nitrogen, carbon dioxide, and others. Oxygen, carbon dioxide, and water are pure substances.

When elements combine to form a compound, the properties of the individual elements change completely, and the compound has its own unique set of properties.

Iron is not a compound but an element. Water, ozone, and carbon dioxide are compounds made up of two or more elements chemically bonded together.

Elements are represented on the periodic table by symbols, which are usually one or two letters derived from their names. Each element has a unique symbol.

Atoms are the basic building blocks of matter. Elements are made up of one type of atom, compounds are made up of two or more types of atoms chemically bonded together, and mixtures are combinations of different substances.

Ammonia is a compound made up of nitrogen and hydrogen chemically bonded together. Hydrogen, neon, and helium are elements.

Silver is an element, not a compound. Baking soda, sugar, and hydrogen peroxide are compounds made up of different elements.

Gasoline is a mixture of different hydrocarbons. Hydrogen, carbon monoxide, and aluminum are pure substances and not mixtures.

Copper is an element with the symbol Cu on the periodic table. Carbon dioxide, vinegar, and methane are compounds or mixtures.

Compounds have molecules, which are two or more different types of atoms chemically bonded together. Elements exist as single atoms and do not form molecules.

Water is a compound made up of two hydrogen atoms and one oxygen atom chemically bonded together. Silver, sulfur, and carbon are elements.

Air is a mixture of different gases like oxygen, nitrogen, carbon dioxide, and others. Gold, sugar, and salt are pure substances.

In a compound, the properties of the individual elements change completely. The compound has its own unique set of physical and chemical properties different from the elements that make it up.

Oxygen is an element, not a compound. Calcium carbonate, water, and aluminum oxide are compounds made up of different elements.

Elements consist of atoms of the same type, all with the same number of protons. Molecules are formed when different types of atoms combine, which is not the case in elements.

Carbon is an element with the symbol C on the periodic table. Hydrochloric acid, sodium chloride, and vinegar are compounds made up of different elements.

A molecule is the smallest unit of a compound that retains the properties of that compound. It is made up of two or more atoms chemically bonded together.

Brass is a mixture of copper and zinc. Iron, copper, and oxygen are pure substances.

Water is represented by the chemical formula H2O, indicating two hydrogen atoms bonded to one oxygen atom. H2O2 is hydrogen peroxide, CO2 is carbon dioxide, and NaCl is sodium chloride (table salt).

Oxygen is an element, not a compound. Table salt, water, and sugar are compounds made up of different elements.

An element is a pure substance made up of only one type of atom. Mixture is a combination of different substances, compound is made up of two or more elements, and isotope is a variation of an element.