Complete question is;
Chemical reactivity of alkali metals increases down the group while reactivity of halogens decreases down the group. Give reasons
Answer:
Explained below
Explanation:
Alkali metals exhibit reactivity due to their electropositivity. Now, for alkalis, their electro-positivity increases down their group. Since their reactivity increases with increase in electropositivity, it means their reactivity also increases down the group.
Whereas, the reactivity of halogens occurs as a result of their electronegativity. Now, electronegativity for halogens decreases down the group. Since their reactivity decreases with decrease in electronegativity, it means that their reactivity will also decrease down the group.
Combustion will cause a chemical change in paper.
This is because the carbon compounds are being oxidized into carbon dioxide and water vapour (or h2o, same thing).
Argon monatomic in nature because it is a noble gas and has completely filled shells and thus does not form a bond with other elements.
Sodium fluoride- to brush teeth
Citric acid- orange juice for breakfast
Sodium hydroxide- cleaning agent