Elements are the simplest forms of matter and therefore cannot be broken down into simpler substances by any chemical or physical means. Each molecule of water is a chemical combination of two hydrogen atoms and one oxygen atom. Water can be decomposed into its elements only by chemical means.

Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means.

A pure substance is something that occurs in nature. An element is made up of one type of atom only and cannot be split further. A compound has the combined properties of the elements from which it is made. A molecule always contains different kinds of atoms.

A substance that cannot be broken down into simpler substances is a pure substance in its lowest form: an element.

A compound is a substance that contains two or more elements chemically combined in a fixed proportion. However, it is not an element because it can be broken down into simpler substances – carbon and hydrogen. Recall that the components of a mixture can be separated from one another by physical means.

(1) CO is a compound that is formed by the chemical combination of two elements, namely carbon and oxygen and we know a compound can be broken down into its constituent elements. (3) Ca is an element and we know element is the simplest form of matter that cannot be further broken down.

Answer Expert Verified. C and Cu cannot be broken down by chemical change.

Potassium can’t be broken down by chemical change because it’s an element, which is the simplest form of matter. Sulfuric acid, ammonia and water are all compounds composed of elements. Compounds can be broken down into simpler compounds or elements by a chemical reaction.

A pure substance cannot be separated into 2 or more substances by physical means such as crystallization or distillation nor by mechanical means such as sifting, filtering, or using a magnet.

Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule.

An element is a pure substance that cannot be separated into simpler substances by chemical or physical means. There are about 117 elements. portion of Earth. Matter that is comprised of (made up of) the same material throughout.

Mixtures – two or more substances that are not chemically combined with each other and can be separated by physical means. The substances in a mixture retain their individual properties. Solutions – a special kind of mixture where one substance dissolves in another.

A mixture is created when two or more different substances are physically combined and can be separated back into its original substances. A chemical reaction occurs when two or more substances are combined to form a new substance and cannot be separated back into its original substances.

Therefore, if a mixture is not a solution then it is a suspension. A mixture is any combination of two or more substances that can be easily separated by physical methods.

Elements can be chemically combined into compounds, therefore, a compound consists of two or more elements combined, in definite proportions, by chemical means. Compounds may be formed by combining atoms of their constituent elements by ionic bonds or by covalent bonds.

In a compound the elements involved (can/cannot) be separated by a simple physical process because the elements are (physically combined/chemically bonded). Each circle represents an atom and each different color represents a different kind of atom. If two atoms are touching then they are bonded together.

Glossary

air is not a mixture because of scientists freezing it and finding different liquids, it is a mixture because the compounds that make up air e.g. oxygen (o2), Carbon dioxide (co2) and the most important Nitrogen which is an element and makes up 78.09% of air are not chemically bound in the way that compounds are …

Air is mostly gas It’s a mixture of different gases. The air in Earth’s atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.