Question

Select all the statements that accurately describe chemical reactions: Question 2 options: The number of atoms decreases when a compound is formed There is the same amount of matter before and after the reaction The atoms are arranged into different compounds or molecules after the reaction The substances in the reaction only undergo a physical change There are the same types and numbers of atoms before and after the reaction

Answer 1

Chemical reactions involve the rearrangement of atoms, but the number and types of atoms remain the same before and after the reaction. The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction.

Step-by-step explanation:

Chemical reactions involve the rearrangement of atoms, but the number of atoms and types of atoms remain the same before and after the reaction. This is known as the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, the statements that accurately describe chemical reactions are:

1. The number of atoms decreases when a compound is formed - This statement is false. The number of atoms remains the same before and after the reaction.
2. There is the same amount of matter before and after the reaction - This statement is true. Matter is conserved in a chemical reaction.
3. The atoms are arranged into different compounds or molecules after the reaction - This statement is true. Chemical reactions involve the formation of new compounds or molecules.
4. The substances in the reaction only undergo a physical change - This statement is false. Chemical reactions involve a rearrangement of atoms, which is a chemical change.
5. There are the same types and numbers of atoms before and after the reaction - This statement is true. The amount and types of atoms remain the same before and after a chemical reaction.

Answer 2

There is the same amount of matter before and after the reaction

The atoms are arranged in different compounds and molecules.

There are the same types and number of atoms before and after the reaction

Step-by-step explanation:

--The same amount of matter before and after the reaction and the same types and number of atoms before and after the reaction is because of the law of conservation of mass. Matter cannot be created or destroyed.

--the reacting atoms and molecules will undergo a transformation to different molecules and compounds. Can be predicted because of the types of chemical reactions:

combination (combining 2 elements to create a new compound)

Decomposition (a compound breaking down into different parts)

Single and Double displacement (the molecules/ atoms will change who they are paired with)