A. NO2 because the elements are both nonmetals.
Answer:
This question will be answered based on general understanding of how a controlled experiment should be:
The answer is: We must make sure we are testing/changing only one variable, and controling others
Explanation:
A controlled experiment is an experiment in which the independent variable is changed for a particular group called the EXPERIMENTAL group and unchanged for another group called the CONTROL group.
In a controlled experiment, only one variable should be tested while the others should be kept constant in order to have an effective result or outcome. This is the case in this question, the type of music or soil should be unchanged for each plant because the experimenter must make sure that he/she is testing/changing only one variable, and controling others.
Answer:
The freezing point of the solution is - 4.39 °C.
Explanation:
We can solve this problem using the relation:
<em>ΔTf = (Kf)(m),</em>
where, ΔTf is the depression in the freezing point.
Kf is the molal freezing point depression constant of water = -1.86 °C/m,
density of water = 1 g/mL.
<em>So, the mass of 575 mL is 575 g = 0.575 kg.</em>
m is the molality of the solution (m = moles of solute / kg of solvent = (465 g / 342.3 g/mol)/(0.575 kg) = 2.36 m.
<em>∴ ΔTf = (Kf)(m</em>) = (-1.86 °C/m)(2.36 m) = <em>- 4.39 °C.</em>
<em>∵ The freezing point if water is 0.0 °C and it is depressed by - 4.39 °C.</em>
<em>∴ The freezing point of the solution is - 4.39 °C.</em>
It gives off a certain colour because when the spectrum is combined........I'm not sure if that's write but i think it is.....not 100% sure tho
Answer : The correct option is, (D) 
Explanation :
(A) 
This reaction is a double displacement reaction in which the cation and anion of two reactants are exchange their places to give two different products.
(B) 
This reaction is a decomposition reaction in which the larger molecule decomposes to give two or more products.
(C) 
This reaction is a neutralization reaction in which an acid and a base react to give a salt and water as a product.
(D)
This reaction is a redox reaction in which the oxidation and reduction reaction occur simultaneously.
Oxidation reaction is the reaction in which a substance looses its electrons. In this oxidation state increases.
Reduction reaction is the reaction in which a substance gains electrons. In this oxidation state decreases.
In this reaction, magnesium shows oxidation due to change in oxidation number from (0) to (+2) and hydrogen shows reduction due to change in oxidation number from (-1) to (0).
Hence, the correct option is, (D)
