D as it only has a negative effect when being used and it is small at that anyway.
Answer:
B. an air-conditioning system.
Explanation:
Refrigeration is defined as a process of cooling a system to lower temperature below the surrounding temperature while the removed heat is rejected at higher temperatures.
Heat pumps use the heat output of the refrigeration process, which may also be designed to be reversible, but are otherwise similar to air conditioning units.
<span>Displaced volume :
final volume - initial volume
32.4 mL - 25.2 mL => 7.2 mL
Density = mass / volume
D = 22.6 g / 7.2 mL
D = 3.1388 g/mL
hope this helps!</span>
Answer:
B: electronegativity
Explanation:
Electronegativity is the measure of how strongly atoms attract bonding electrons to themselves.
A is incorrect because Atomic radius though decreases as you go from lithium to fluorine of the periodic table. Atomic radius increases when you go from either top to bottom of the periodic table, or if you go from right to left. So answer A is inaccurate.
C is incorrect because in period 2, all the elements have two electron subshells. For example, Al has 13 electrons. So it has two electron subshells. This is since the first subshell has only two valence electrons and while the second subshell in Al has 11 valence electrons. Therefore, it is inaccurate to say this answer.
D is incorrect because in the first shell, you can only have a max of two electrons. The first shell neither decreases or increases. Therefore, D is inaccurate too.
B is correct because as you go from the periodic table from left to right, the electronegativity and ionization energy increases. This is since the more valence electrons an element has, the more electronegative is. Fluorine for example is desperately trying to get one more electron to have a total of 8 electrons. It wants to have a full shell. Therefore, B is the most relevant answer.
A. Atoms only. An element cannot be separated into simpler materials
