Answer:
B. Atoms in the original substances are arranged in a different way to make new substances.
Explanation:
The best statement that describes a change that occurs in a chemical reaction is that atoms in the original substances are arranged in a different way to make new substances.
- Chemical reactions obey the law of conservation of matter.
- The law postulates that "matter is neither created nor destroyed in a chemical reaction but they are simply rearranged".
- Therefore, atoms of compounds forms new bonds by rearranging to give a new product.
One mole is always the same number: 6.02 * 10^ 23.
So, one mole of cars = 6.02 * 10 ^23 cars; one mole of pencils = 6.02 * 10^23 pencils; one mole of atoms = 6.02 * 10^23 atoms; one mole of molecules = 6.02 * 10^23 molecules.
So, all the options are correct: one mole of calcium ions has 6.02 * 10^23 representative particles, such as one mole of calcium nuclei and one of calcium atoms.
Answer:
54 g
Explanation:
1 mole of water = H2O
mass of 1 mole of H2O= mass of h2 + mass of o
= 2× mass of h +mass of o
= 2×1+16 =18 g
1 mole of water = 18g
3moles of water = 18×3g= 54g
