Na is a metal
N is a nonmetal
thus, they form an ionic bond, where electrons are transferred from the metal, to the nonmetal
The best answer among the choices given that describes compression would be "<span>region of high pressure in a medium caused by a passing wave." The concepts of air compression is widely used in the industries such as vehicle tires, balloons, and other inflatable materials requiring high air pressure.</span>
Use a periodic table. Count the exponent for your atomic number. So, 1s2 2s2 2p5= Fluorine
1s2 2s2 2p6 3s2 3p5= Chlorine
1s2 2s2 2p6 3s2 3p6 4s2 3d6= Iron
Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.
<h3>What is the hardness of any element?</h3>
The hardness of any element may be defined as the capability of a material to oppose the process of deformation and remains in actual shape precisely.
According to the table of hardness scales by Mohs, the increasing order of given hardness of given elements is as follows:
Gypsum < Fluorite < Apatite.
Therefore, Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.
To learn more about the Hardness of elements, refer to the link:
brainly.com/question/23721736
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