In an experiment, a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean magnesium ribbon was placed in a crucible and completely burnt in oxygen
After cooling the product weighed 4.0g To remune
a) Explain why it is necessary to clean magnesium ribbon
b) What observation was made in the crucible after burning magnesium ribbon?
c) Why was there an increase in mass?
d) Write an equation for the major chemical reaction which took place in the crucible
e) The product in the crucible was shaken with water and filtered. State and explain the
observation which was made when red and blue litmus paper were dropped into the filtrate​

chemical energy is stored in the chemical bonds of atoms and molecules. it can only be seen when it is released in a chemical reaction. when chemical energy is released, the substance from which the energy came is often changed into an entirely different substance.

this chemical reaction releases energy in the form of light and heat. chemical energy is the potential energy stored in the arrangement of atoms within molecules. breaking chemical bonds requires energy, while forming new chemical bonds releases energy.

the atp molecule can store energy in the form of a high energy phosphate bond joining the terminal phosphate group to the rest of the molecule. in this form,energy can be stored at one location, then moved from one part of the cell to another, where it can be released to drive other biochemical reactions.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

c) should be the answer.