For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
<u>Answer:</u> In the reaction, magnesium atoms lose electrons.
<u>Explanation:</u>
An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom. These are usually formed when a metal reacts with a non-metal or a metal reacts with a polyatomic ion or a reaction between two polyatomic ions takes place.
Magnesium is 12th element of the periodic table having electronic configuration of 
This element will loose 2 electrons to form 
ion
Chlorine is 17th element of the periodic table having electronic configuration of 
This element will gain 1 electron to form 
ion
By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.
The ionic compound formed is 
Hence, in the reaction, magnesium atoms lose electrons.
Answer:
73.68 J
Explanation:
To find the energy absorbed by nickel, you need to use the following equation:
Q = mcΔT
In this equation,
-----> Q = energy (J)
-----> m = mass (g)
-----> c = specific heat (J/g°C)
-----> ΔT = change in temperature
The change in temperature is found by subtracting the initial temperature from the final temperature. You can plug the given values into the equation and simplify to find the energy absorbed.
m = 10.0 g
c = 0.120 J/g°C
ΔT = 63.4 °C - 2.0 °C = 61.4 °C
Q = mcΔT
Q = (10.0 g)(0.120 J/g°C)(61.4 °C)
Q = 73.68 J
The answer is D: Salt and Water
Nonmetals have the ability to attract electrons better than metals because they have a higher electron affinity or electronegativity than metals.
<h3>What is electronegativity?</h3>
Electronegativity is the tendency, or a measure of the ability, of an atom or molecule to attract electrons and thus form bonds.
An element in the periodic table with a high electronegativity will automatically have a high electron affinity.
Metals (low electronegativity) are known to lose electrons to non-metals (high electronegativity), hence, nonmetals have the ability to attract electrons better than metals because they have a higher electron affinity or electronegativity than metals.
Learn more about electronegativity at: brainly.com/question/2060520
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