there is more air near sea level
Heated mater rises and cold mater sinks
Answer:
I would use calorimetric to determine the specific heat and I would measure the mass of a sample
Explanation:
I would use calorimetry to determine the specific heat.
I would measure the mass of a sample of the substance.
I would heat the substance to a known temperature.
I would place the heated substance into a coffee-cup calorimeter containing a known mass of water with a known initial temperature.
I would wait for the temperature to equilibrate, then calculate temperature change.
I would use the temperature change of water to determine the amount of energy absorbed.
I would use the amount of energy lost by substance, mass, and temperature change to calculate specific heat.
Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
Answer:
[OH-] = 6.17 *10^-10
Explanation:
Step 1: Data given
pOH = 9.21
Step 2: Calculate [OH-]
pOH = -log [OH-] = 9.21
[OH-] = 10^-9.21
[OH-] = 6.17 *10^-10
Step 3: Check if it's correct
pOH + pH = 14
[H+]*[OH-] = 10^-14
pH = 14 - 9.21 = 4.79
[H+] = 10^-4.79
[H+] = 1.62 *10^-5
6.17 * 10^-10 * 1.62 * 10^-5 = 1* 10^-14
