Which of the following is/are postulates of Dalton’s atomic theory? 1. Atoms combine in fixed ratios of whole numbers. 2. Atoms of each element have different properties. 3. Elements occur as solids, liquids, or gases. Group of answer choices

1 and 2

Explanation:

The postulates of Dalton's atomic theory are;

- Matter is made up of indivisible particles known as atoms.

- Atoms of same elements have same properties while atoms of different elements have different properties.

- Atoms of different elements combine in fixed ratios to form compounds.

- Atoms are neither created nor destroyed.

- The formation of new products (compounds) results from the rearrangement of existing atoms (reactants).

By comparing the postulates above and those in the questions, we find that only the following postulates are part of the daltons atomic theory;

1. Atoms combine in fixed ratios of whole numbers.

2. Atoms of each element have different properties.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-