There are 118 elements in the periodic table.
Answer:
The cooler water is denser
Explanation:
Convection drives the boiling of water placed on a stove in a kettle.
During convection, heat is circulated by density differences in portions of a fluid.
Convection is a form of heat transfer in fluids especially gas and liquid.
- In boiling water, the heat is supplied to the base of the stove.
- The water at the bottom on heat becomes lighter as the molecules gain more kinetic energy.
- The colder part of the water on top sinks to replace the less dense on below.
- This exchange sets up convection cells in the kettle.
Answer:
0.56L
Explanation:
This question requires the Ideal Gas Law: 
where P is the pressure of the gas, V is the volume of the gas, n is the number of moles of the gas, R is the Ideal Gas constant, and T is the Temperature of the gas.
Since all of the answer choices are given in units of Liters, it will be convenient to use a value for R that contains "Liters" in its units:
Since the conditions are stated to be STP, we must remember that STP is Standard Temperature Pressure, which means 
and 
Lastly, we must calculate the number of moles of 
there are. Given 0.80g of , we will need to convert with the molar mass of . Noting that there are 2 oxygen atoms, we find the atomic mass of O from the periodic table (16g/mol) and multiply by 2: 
Thus, 
Isolating V in the Ideal Gas Law:
...substituting the known values, and simplifying...
So, 0.80g of would occupy 0.56L at STP.
