Ionic bonds are formed when a cation and an anion transfer electrons. The anion gains electrons from the cation to finish its shell, and is usually a nonmetal or a metalloid. A cation gives the anion its electrons to get rid of its partial shell. Cations are metals.
Arsenic, I believe. Metalloids fall in between metals and nonmetals (usually on the bold line separating the two on the periodic table). And since the metalloid in question has four electron shells and five valence electrons in the outermost shell, you can see that this element is arsenic
Answer : The amount of formaldehyde permissible are, 
Explanation : Given,
Density of air =

First we have to calculate the mass of air.



Now we have to calculate the amount of formaldehyde.
Permissible exposure level of formaldehyde = 0.75 ppm = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Thus, the amount of formaldehyde permissible are, 
6_____18 record your data to be used in the following problem.
Answer:
Explanation:
1) NaCl → Na + Cl₂
2) Na + HCl → NaCl + H₂
Chemical equation:
NaCl → Na + Cl₂
Balanced chemical equation:
2NaCl → 2Na + Cl₂
There are two moles of sodium and two mole of chlorine on both side of equation so given chemical equation is correctly balanced and follow the law of conservation of mass.
2)
Chemical equation:
Na + HCl → NaCl + H₂
Balanced chemical equation:
2Na + 2HCl → 2NaCl + H₂
There are two moles of sodium and two mole of chlorine and hydrogen on both side of equation so given chemical equation is correctly balanced and follow the law of conservation of mass.
Law of conservation mass
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.