Hello there!
An Atom would be considered to be the smallest unit that would make up matter. If were to ever see a picture of an atom, they would consists of a proton, neutron, electron, and a nucleus. And all this would be called a Atom.
Your answer: Atom
Answer:
Gaseous nitrogen has unique chemical and physical properties that make it suitable for use in food processing. Nitrogen is inert which means it will not react with prepared food materials, which can alter their aromas or flavors. Also, gaseous nitrogen will effectively displace oxygen minimizing oxidation and the growth of microorganisms that cause foods to lose their freshness and deteriorate faster.
Explanation:
Source: https://www.generon.com/using-nitrogen-gas-in-food-packaging/
Um i think gold... i think?
Chlorine + Calcium --> Ionic Bond
Iron cannot covalently bond as it is a metal
Answer: 116 g of copper
Explanation:

where Q= quantity of electricity in coloumbs
I = current in amperes = 24.5A
t= time in seconds = 4.00 hr =
(1hr=3600s)

of electricity deposits 63.5 g of copper.
352800 C of electricity deposits =
of copper.
Thus 116 g of Cu(s) is electroplated by running 24.5A of current
Thus remaining in solution = (0.1-0.003)=0.097moles