Answer:
HCL, NACL and CO are the examples of chemical formulas
Answer: (a) There are 0.428 moles present in 12 g of
molecule.
(b) There are 2 moles present in
particles of oxygen.
Explanation:
(a). The mass of nitrogen molecule is given as 12 g.
As the molar mass of
is 28 g/mol so its number of moles are calculated as follows.

So, there are 0.428 moles present in 12 g of
molecule.
(b). According to the mole concept, 1 mole of every substance contains
atoms.
Therefore, moles present in
particles are calculated as follows.

So, there are 2 moles present in
particles of oxygen.
Because things that are burnt have been changed into something else like moldy bread thats cooked.
It is chemical change because you cannot unburn something.
Answer:
All of these compounds are made from the element copper. Copper Acetates, Cuprous Oxide, Cupric Oxide (otherwise know as black copper oxide), Cupric Chloride, Copper Oxychloride, Cuprous Chloride, Cupric Nitrate, Copper Cyanide.
Explanation:
Copper is considered an element. You can use copper for Jewelry, Table Tops, Sinks, Dark Chocolate, Leafy Greens, Lobster, Nuts and Seeds, Mushrooms, Oysters, Liver and etc other nutrience. Copper is an easily molded base metal that is often added to precious metals to improve their elasticity, flexibility, hardness, colour, and resistance to corrosion.