"People should remove native plants around watersheds" option should a person avoid doing in order to better protect the quality of watersheds.
<u>Option: A</u>
<u>Explanation:</u>
Watershed is basically a source of large amount of water like river, sea, etc to another location like lake, ponds and stream.This is seen majorly during rainy season by water harvesting to supply further for farming, portable water plant, manufacturing sectors, enrich habitat to number of plants and animals, etc. Waterways face issues when erosion, pollutants and runoff of animal waste take place, which act as barrier for water flow, as it decreases the quality which affect aquatic animals life, reduce oxygen content. Native plants near watersheds is also a habitat for many animals and species thus it should not be removed until some major flaw occurs.
Answer : The correct option is, (b) 22.5 M
Explanation : Given,
Mass of calcium nitrate tetrahydrate = 266 g
Molar mass of calcium nitrate tetrahydrate = 236.15 g/mole
Volume of solution = 
Molarity : It is defined as the moles of solute present in one liter of solution.
Formula used :
Now put all the given values in this formula, we get:
As calcium nitrate tetrahydrate dissociate to give 1 mole of calcium ion, 2 moles of nitrate ion and 4 moles of water.
The concentration of nitrate ion = 
Thus, the concentration of nitrate ion is, 22.5 M
Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
Answer:
The physical and chemical properties of the product do not match the properties of the reactant.
Explanation:
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
These changes occur due to chemical reactions
These may not be observed with naked eye
Example:
Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood
Boiling of egg: that change the chemical composition of protein in the egg .
The reaction of Hydrogen and oxygen:
H 2 (g) + O 2 (g) -------------------------------------> 2H 2O (l)
The reaction between sugar and oxygen form a product which is different from the reactant that's why it indicate the occurrence of chemical reaction.
While in case of physical changes just state of matter are changed. Properties remain same.
