Answer: The number of protons and the number of neutrons determine an element's mass number.
Explanation:
Answer:
Endothermic
It absorbs heat
1.20 × 10³ kJ
Explanation:
Let's consider the following thermochemical equation.
2 H₂O(l) → 2 H₂(g) + O₂(g) ΔH = 572 kJ
Since ΔH > 0, the reaction is endothermic, that is, it absorbs heat when H₂O reacts.
572 kJ are absorbed when 36.03 g of water react. The heat absorbed when 75.8 g of H₂O react is:
75.8 g H₂O × (572 kJ/36.03 g H₂O) = 1.20 × 10³ kJ
Answer:
0.136g
Explanation:
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?

Initial mole of Co(NO3)2 

Mole of Co(NO3)2 in final solution

Mole of NO3- in final solution = 2 x Mole of Co(NO3)2

Mass of NO3- in final solution is mole x Molar mass of NO3

Answer:
Temperature gradient = 30
90F - 60F = 30F
The temperature gradient is 30F.
If I am right, let me know.
Answer:
Wave 2
Explanation:
Higher frequency means more energy per second, And wave 2 has higher frequesncy
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