Which scenarios are examples of physical changes? check all that apply. wood is burned in a campfire and is turned into ash and smoke. silicon is cut into tiny pieces for computer chips. lead is melted to form pellets. liquid water freezes to form ice. yeast turns sugar into energy, water, and carbon dioxide gas.

Check these:

- Silicon is cut into tiny pieces for computer chips.
- Lead is melted to form pellets.
- Liquid water freezes to form ice.

Explanation:

Physical changes do not change the chemical composition fo the substance. When you cut Silicon the atoms remain being atoms of silicon (Si), when you melt lead (Pb), the atoms of lead continue being atoms of lead, when you freeze water the molecules continue being molecules of water (H2O).

On the other hand when the wood id burned, the original hydrocarbons that consitute it transform into other king of substance: CO2 + water + CO, so this is a chemical change.

Also, yeast is tranformed into other substances,which is, again, a chemical change.

The silicon, the lead, and the water have been physically changed.

The wood and the yeast have been chemically changed.

It won't lose or gain electrons if it's a covalent bond it shares the electrons with another atom or atoms. if it is an ionic bond it will lose the 3 electrons on the outer shell and become a positively charged ion.  credit goes to @sunshinebaby of answers.yahoo.com.

This did i unseated, sorry