A chemical change affects on the molecular level of matter, which makes it irreversible. Combustion is a pretty good exmple. Physical changes are reversible and dont alter the formula. Hope this helped!
Answer:
Copper is element number 29
4th row
11th column
1. HCl (H:1, Cl 35.5) ---> 1+35.5 = 36.5
2. FeS (Fe:56, S:32) ---> 56+32 = 88
3. Cl2 (Cl:35.5) ---> 35.5 x 2 = 71
4. CaC03 (Ca:40, C: 12, O: 16) ---> 40 + 12 + 3(16) = 100
5. Fe0 (Fe: 56, O: 16) ---> 56+16=72
Orbitals am only hold two electrons each, so 3 orbitals can hold 6 electrons
Answer:
800 degrees C g, I found this answer by using the formula to find how much energy was need to melt the ice. First you figure out the temperature change of ur ice (starting temp and ur final temp), and then you times that with the mass of the water.