Answer:
A small positively charged nucleus surrounded by revolving negatively charged electrons in fixed orbits
Answer:
Melting of ice
Explanation:
A physical change is one in which just the physical properties of the matter is altered. Most phase changes reaction falls under this type of change.
- Examples are boiling, melting, freezing, condensation, sublimation, magnetization of metals, breaking glass, cutting wood.
- No new kinds of matter is formed.
- The process is reversible
- No change in mass
Answer:
6. In order from left to right the balanced coeficcients are,
6, 1, 2, 3
8. 
9. In order from left to right the balanced coeficcients are,
1, 11, 7, 8
Explanation:
Start with a balanced equation.
2H2 + O2 → 2H2O
Assuming that H2 is in excess, multiply the given moles H2O by the mole ratio between O2 and H2O in the balanced equation so that moles H2O cancel.
5 mol H2O × (1 mol O2/2 mol H2O) = 2.5 mol O2
Answer: 2.5 mol O2 are needed to make 5 mol H2O, assuming H2 is in excess.
