Some examples of physical changes are:
Breaking a glass
Chopping wood
Tearing paper
Mixing sand and water
Melting an ice cube
These all are physical changes because the composition of the matter does not change.
Answer:

Explanation:
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In this case, since 12.75 g of calcium iodide has the following number of moles (molar mass = 293.89 g/mol):

In such a way, since 1 mole of calcium iodide contains 2 moles of atoms of iodine, and one mole of atoms of iodine contains 6.022x10²³ atoms (Avogadro's number), we compute the resulting atoms as shown below:

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1. carbon lies in the 2nd period where silicon in the third period.
2. carbon is a non metal whereas silicon is a metalloid.
3. there are only 3 isotopes of carbon and 23 isotopes of silicon
4. size of silicon atom is larger
5. silicon is heavier than carbon.
Answer : Mass
Explanation : Mass measures the amount of matter in a substance or an object.
The reactant is Mercury (II) Oxide while the products are Mercury and Oxygen separately.
This is because the reactants are typically always on the left side of the yields symbol. In this decomposition reaction, it would still be the same as at the end of the reaction, there were to products produced: Mercury and Oxygen.
Products tend to always be on the right side of the yields symbol, they're what comes out of a reaction no matter what type.
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