Question

Science Class VII - CHAPTER 6 ( PHYSICAL AND CHEMICAL CHANGES ) ANSWER THE FOLLOWING QUESTIONS PLEASE GUYS​

Answer 1

Answer

1.Reactants

2.Chemical Change

3.A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.

4.Compounds

5.Hydrochloric acid HCL

Answer 2

Answer:

1.These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.

2.All chemical changes are irreversible changes. Once the chemical properties of a substance are changed, it becomes another substance. Thus, it cannot return to its original state.

3. Chemical identity means a name that will uniquely identify a chemical.

4.Element-An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron.

5.Acetic acid formula-CH3COOH

Explanation:

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