The right answer for the question that is being asked and shown above is that: "<span>2)A gas forms, and there is a change of color. " </span>During an experiment, a student observes the formation of a precipitate. a chemical reaction is likely occurring because <span>A gas forms, and there is a change of color.</span>
Answer:
The options a and b are correct
Explanation:
This options provided to the question are the answers to the question. But for clarification. When the fat melts, the change of state that occurs here is from solid to liquid (which is called melting) while the change of state that occurs when the water evaporated is from liquid to gas (which is called evaporation).
Answer:
Coal puts out more Co2 emissions than Oil or Gas and Nuclear energy plants don't put out any pollution.
Explanation:
Even though Coal is your answer it is actually a very clean form of generating energy. Not only is it very clean but it is the most effecient means. Solar and Wind power can't even come close to the production and turnover that Coal, Gas, and Oil can. Wind Turbines are so innefficent that they somtimes don't even pay off what it took to build them in thier lifetime of service. The production of Wind Turbines puts out more pollution than any of the Coal or Natural Gas Plants. Solar power is not very efficent either but it is on it's way. It is also very expensive.
The complete answer contains the answer choices.
This is the complete question:
Atoms of which element react spontaneously with Mg2+(aq)? (1)chromium
(2)barium
(3)iron
(4)zinc
Answer: option 2. barium.
Explanation.
1) Mg ²⁺ (aq) is the aquous cation of the metal Mg.
2) Only a metal more reactive than Mg will be able to exchange with it the oxidation states.
3) Mg is an earth alkalyne metal (group 2 of the periodic table). The metals from this group are more reactive than the metals in the groups to its right: 3, 4, 5, 6, 7, ... Only the alkalyne metals (those in group 1) are more reactive than the earth alkalyne metals.
4) Of the list, barium is the only alkalyne metal, so it is more reactive than Mg and will be able to deliver 2 electrons to transform the cations Mg²⁺ into Mg while the very Ba will become Ba²⁺.
5) Chromium, iron and zinc are transition metals, so less metallic (reactive) than Mg.
