Question

Which substance can be broken down by chemical means? (1) CO (3) Ca (2) Ce (4) Cu

Answer 1

The substance that can be broken down by chemical means is $\boxed{{\text{(1)CO}}\;}$

Further explanation:

Pure substances

The substances that are made up of only one kind of atoms or molecules are known as pure substances. It is generally called as a chemical substance. Any substance is also said to be pure if it has a constant composition. Water, tin, diamond, sulfur, sodium chloride are some of the examples of pure substances.

Pure substances are of two types:

1. Elements:

An element is the simplest form of substance that cannot be broken down by any chemical methods. Every element has its own characteristic atomic number that is used to distinguish it from other elements. Copper, iron, neon, cobalt are examples of elements.

2. Compounds:

These are the substances formed by the chemical combination of two or more elements in a specific ratio. If the same elements are mixed in any other ratio, different compounds will be formed. These can be further broken down into their constituent elements.

Mixtures:

The material that is made up of two or more substances is called a mixture. It has no fixed formula and has a variable composition. All the individual constituents retain their properties after the formation of the mixture. Air, blood, concrete, and soda are some examples of mixtures.

(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. So this is a correct option.

(2) Ce is an element and we know element is the simplest form of matter that cannot be further broken down. So this is an incorrect option.

(3) Ca is an element and we know element is the simplest form of matter that cannot be further broken down. So this is an incorrect option.

(4) Cu is an element and we know element is the simplest form of matter that cannot be further broken down. So this is an incorrect option.

Learn more:

1. Which sample is a pure substance: brainly.com/question/2227438

2. Example of physical change: brainly.com/question/1119909

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Elements, compounds, and mixtures

Keywords: mixture, pure substance, element, compound, chemical means, methods, formula, substances, composition, individual, constituents, Ce, CO, Cu, Ca, substance, broken down.

Answer 2

The substance that can be broken down by chemical means from the choices given is CO  (Carbon monoxide).

Carbon monoxide is a compound made up of carbon and oxygen and can therefore be broken by chemical means.

Further Explanation

Pure substances  

• Pure substances are substances that have a constant composition and also cannot broken down into simpler substances using physical means.

• Pure substances are classified as either elements or compounds.

Elements

• Elements are a type of pure substances that are made up of one type of atom and cannot be broken down into simpler substances by both chemical and physical means.
• Atoms making up a certain element are similar or identical in properties. Examples of elements are, Oxygen, sodium, calcium, etc. Periodic table shows an arrangement of all known elements.

Compound  

• A compound is a pure substance that is made up of than one type of atoms of different elements and can be broken down into individual elements making it using chemical means.
• Compounds cannot be broken down into simpler substances by physical means but only using chemical means. Compounds have constant composition and therefore they have a constant ratio of elements. For example the ratio of elements making up carbon dioxide is always 27% Carbon and 73% Oxygen.
• Examples of compounds include, water, Ammonia, calcium sulfate, carbon dioxide, etc.
• In our case, Carbon monoxide, (CO) is a compound made up of a carbon atom and an oxygen atom. Other choices, Ca, Ce, and Cu are all elements.

Keywords: Compound, elements, pure substances  

Learn more about:

• Compounds: brainly.com/question/9493916
• Pure substances: brainly.com/question/12637406
• Elements: brainly.com/question/12443572

Level: High school

Subject: Chemistry  

Topic: Atoms, elements, compounds and mixtures