Question

1. which statement is one of the postulates in daltons atomic theory?

atoms of one element can change into atoms of another element if they undergo a chemical reaction.
physical reactions occur when atoms are separated, joined, or rearranged.
atoms cannot be separated, joined, or rearranged.
compounds are formed when atoms of an element combine with other atoms in whole number ratios.

Explanation:

• Atoms of one element can change into atoms of another element if they undergo a chemical reaction: Dalton's atomic theory states that atoms of one element cannot be changed into atoms of another element. Atoms are indivisible in chemical reactions.
• Physical reactions occur when atoms are separated, joined, or rearranged: Dalton's theory is about chemical reactions. Chemical reactions involve separation, joining, or rearrangement of atoms, not physical reactions.
• Atoms cannot be separated, joined, or rearranged: This is incorrect. In chemical reactions (as per Dalton's theory), atoms are separated, joined, or rearranged.
• Compounds are formed when atoms of an element combine with other atoms in whole - number ratios: This is one of the postulates of Dalton's atomic theory. Dalton proposed that compounds are formed by the combination of atoms of different elements in simple whole - number ratios.

Answer:

Compounds are formed when atoms of an element combine with other atoms in whole number ratios.