Answer:different elements have different number of electrons and shells/orbits thatswhy it have different atomic mass and size.
Explanation:
Answer:
The circulatory system.
Explanation:
All of them are in charge of pumping blood and oxygen throughout the body, which is the job of the circulatory system.
Answer:
The answer to your question is given below.
Explanation:
To prepare 50mL of 3M HCl, we must calculate the volume of the stock solution needed. This can obtained as follow:
Molarity of stock solution (M1) = 12M
Volume of stock solution needed (V1) =?
Molarity of diluted solution (M2) = 3M
Volume of diluted solution (V2) = 50mL
The volume of the stock solution needed can be obtained by using the dilution formula as shown below:
M1V1 = M2V2
12 x V1 = 3 x 50
Divide both side by 12
V1 = (3 x 50)/12
V1 = 12.5mL
The volume of the stock solution needed is 12.5mL
Therefore, to prepare 50mL of 3M HCl, we must measure 12.5mL of the stock solution i.e 12M HCl and then, add water to the mark in a 1L volumetric flask. Now we can measure out 50mL of the solution.
1 CH4 (g) + 2 O2 (g) -----> CO2 (g) + 2H2O(l) ΔH= - 890 kJ
1 mol 2 mol
1) If ΔH has minus, it means "release". We need only "release" choices.<span>
2) From reaction
1 mol </span>CH4 (g) "releases" ΔH= - 890 kJ - We do not have this choice.
2 mol O2 (g) "release" ΔH= - 890 kJ, so
1 mol O2 (g) "release" ΔH= - 445 kJ
Correct answer is B.
