Answer:
The first is true
The second is true IF the statement means that the human body contains energy
The third is true
The fourth is false
Let's use Boyle's Law here. P1*V1 = P2*V2
Given: (assuming that there are decimals at the end for Sig Figs)
P1 = 900.mmHg
P2 = 1140.mmHg
V1 = ???
V2 = 250.mL
900.mmHg* ??? = 1140.mmHg * 250.mL
??? = 1.27*250.mL
??? = 318.mL
Therefore, the original volume is 318mL.
Answer:
This metal could be the aluminium with a specific heat of 
Explanation:
A pie of unknown metal presents a mass (M) of 348 g. This metal is heated using energy (E) of 6.64 kJ and the temperature increases from T1 =24.4 to T2 =43.6°C. We can calculate the specific heat (H) of this metal as follows

We can replace previously presented data in this equation. After simplifying and converting to adequated units, we found that

Finally, the specific heat of this metal is

The aluminium could be the metal, its specific heat is similar to that found in this problem.
Finally, we can conclude that this metal could be the aluminium with a specific heat of 
Places with high altitudes will have cold climates.
Answer:
Na+ is positively charged as it loses an electron
Cl- is negatively charged as it gains an electron