Answer:
Phase change from a liquid to a gas occurring at a specific temperature and pressure
Explanation:
Boiling is a physical process in which a substance changes its state from liquid to vapor state.
In this context ,boiling point is the threshold temperature at which changes of state from liquid to vapor occurs. The boiling point also depends upon atmospheric pressure of environment as well. For the same substance, boiling point at two different pressure will differ significantly.
For example : Boiling point of water at sea level is 100 degree Celsius
while at 6,250 ft , Boiling point of water is 93.4 degree Celsius.
Based on above discussion option B Phase change from a liquid to a gas occurring at a specific temperature and pressure is the correct answer.
Answer:
C. Br and Cl
Explanation:
The pair that will share electrons when a bond forms between them is Br and Cl.
When electrons are shared between two atoms to form a bond, then the bond type formed is called a covalent bond.
- A covalent bond forms between non-metals.
- Br and Cl are non-metals
- The electronegativity difference between the species must be very low or zero.
- This is the case for the two non-metals.
Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
Explanation:
Moles of Oxygen = 64/16 = 4
Moles of Hydrogen = 8/1 = 8
Hence the empirical formula is H2O.
Answer:
Calcium is heavier a little bit
