Answer:
Its atomic number is 14 and its atomic mass is 28. The most common isotope of uranium has 92 protons and 146 neutrons. Its atomic number is 92 and its atomic mass is 238 (92 + 146).
Answer:
eukaryotic, which contain a nucleus, and prokaryotic, which do not. Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular.
Explanation:
I'm not sure, I think he'll mess everything because he can't see. Let me know if this helped ♂️
Answer:
The oxygen O2, and the carbon dioxide (CO2) dissolved in water are very important to keep live in aquatic bodies.
Explanation:
Oxygen (O2) is an element found in nature usually as a gas in the air that we breathe. Oxygen is very important for aerobic organisms, including us, the humans. It can dissolve in water, and it is vital for the health of aquatic habitats. If we have low quantity of oxygen dissolve in water means that could be a pollution problem. Actually the oxygen level is an indicator to determine the water quality. In order to survive the aquatic biota (animals and plants) need certain quantity of oxygen. The oxygen dissolved in the water comes from the air, because of the wind, rain, waves, currents, and from aquatic plants like algae thanks to a process call photosynthesis.
Carbon Dioxide (CO2) is a chemical compound. This gas also is found in the air, and can be dissolved in water easier than oxygen. Aquatic plants needs CO2, to produce their own food during the photosynthesis process. It´s very important to have enough CO2, for the growth of aquatic plants. But if we have to much CO2 the fish will not have enough oxygen and could suffocate and die. Aquatic animals through respiration process produce CO2, it also can be obtained from fermentation, and from the burning of any substance that has carbon C.
If we want to preserve live in the aquatic bodies we must keep the balance between oxygen and carbon dioxide.
Answer: -1835 kJ
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
Net chemical equation:
(3)
Multiplying equation (1) by 4, and reversing we get
(4)
Adding (2) and (4)
Thus enthaply change for the reaction is -1835 kJ.
