M = 22.1 g
V = 52.3 mL
D = ?
D = m/V
= 22.1/52.3
= 22.1*10/52.3*10
= 221/523
= 0.4
There. I’m sorry i forgot what exactly was the S.I. unit of density :(
We have that energy=specific heat * change in temperature * mass. Thus, we have the final temperature (22) minus the initial temperature (55) to equal -33 as our change in temperature. Our specific heat is in J/g*C, so we're good with that because g stands for grams and the aluminium is measured in grams. As there are 10 grams of aluminum, we have

as our final temperature
An exothermic reaction would release energy and would therefore lose heat itself, while an endothermic reaction would absorb energy and gain heat. Therefore, losing heat would be an exothermic reaction
Feel free to ask further questions!
Answer:
1120 L.
Explanation:
Hello!
In this case, as no conditions of pressure of temperature are given for this problem, we can assume that the scuba diver dives at STP (1 atm and 273.15 K), which means that 1 mole of air would occupy a volume of 22.4 L.
In such a way, since she needs 50.0 moles of air, the following ratio is useful to compute the size (volume) of the tank she needs:

Thereby, we plug in to obtain:

Best regards!
The correct option is B.
Isotopes refers to those chemical compounds which have the same number of protons and electrons but different number of neutrons, so they end up having different mass numbers. The diagram given above is that of beryllium, which has atomic number 4 and it has 2 electrons in its outermost shell. It has four protons [same as the number of electrons] and 5 neutrons. Beryllium 10, which is its isotope has four electrons, four protons and 6 neutrons. To get the number of neutron, remove the number of electrons from the number given in the option, that is, 10 - 4 = 6.
Answer:
The big energy change when water freezes is in the potential energy of interactions between the water molecules.
Explanation:
I am not to sure if this is correct, but I hope it helps in some way.