Answer:
Electrons on the outermost shell of an atom. They are responsible for the chemical properties of an atom.
Answer:
Gets exposed to oxygen (or water)
Explanation:
It's called oxidizing.
1.) A compound is a substance that originates from two or more separate elements. It shares some similarities with a mixture.
2.) A compound has quite different properties from which it was formed. It also cannot be separated easily. Compounds are formed by chemical reactions.
3.) A pure substance has a constant composition and has consistent properties. It can be a compound or an element, but its composition is constant.
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Answer:
Both are endothermic reactions.
Explanation:
Chemical equation:
1/2H₂(g) + 1/2I₂(g) → HI(g) + 6.2 kcal/mol
Chemical equation:
21.0 kcal/mol + C(s) + 2S(s) → CS₂
Both reaction are endothermic because heat is added in both of reactions.
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Answer:
It is
D- <u><em>DEFINE</em></u> the problem
R-<em><u>RESEARCH</u></em> on the problem
H- Carry out a <u><em>HYPOTHESIS</em></u>
E- carry out an <em><u>EXPERIMENT</u></em>.
R-Analyse the <u><em>RESULT</em></u>
C-summarise the <u><em>CONCLUSION</em></u>.
Explanation:
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