Answer:
17.4 cm
Explanation:
Power of lens = +1.75 diopters
Focal length of lens

This is a convex lens as focal the diopter given is positive which makes the focal length positive. Image distance will be negative.
v = -25

∴ The new near point is 17.4 cm
Water breaks down into hydrogen and oxygen: It is a decomposition reaction as a single substance decomposes to give two products.

Leaves make starch using chlorophyll and carbon dioxide: Synthesis reaction: as the synthesis reaction involves two or more than two reactants which join together to result into a single main product along with the formation of simple by products.

Food burns in oxygen gas and releases a lot of energy: Combustion: Combustion process involves the use of oxygen to give products along with release of energy.

Adding vinegar (acid) to baking soda (alkali) gives a product that is neither acidic nor alkaline: Neutralization: acetic acid in vinegar reacts with soda (base) to give salt (neutral) and .

Answer:
Yes the valency of oxygen is 2
Metals
3/4 of the periodic table
Good conductors of heat and electricity
Malleable
Nonmetals
1/4 of the periodic table
Bad conductors of heat and electricity
Not bendable