Questions

The payback period is how long it takes to recoup your investment. In this example, the cost was $4,000,000 and the savings was $800,000 per year. $4,000,000/$800,000 = 5. Therefore, Answer A, B and D are incorrect.

Tropical Deciduous Forests: They are also called the “Monsoon forests”. They grow in the areas with annual rainfall of 70-200 cm. Sandal wood, Shisam, Mahua, Sal, Teak and Bamboo are important species of trees. Moist deciduous and the dry deciduous forests are two major categories of these forests.

The given compound is NaHCO3 Sodium bicarbonate which is commonly known as Baking soda.

Oxidation numbers are the charges on ions. When a neutral atom loses electrons it becomes positively charged. When a neutral atom gains electrons it becomes negatively charged.

Here the C represents the oxidation state of carbon in this compound. Compounds are electrically neutral, which is why we set the sum of the oxidation states equal to zero.

Sodium has a +1 oxidation state. Hydrogen has a +1 oxidation state. Oxygen has a -2 oxidation state. There are three oxygen atoms, which means the total oxidation state provided by both oxygen ions is -6. Adding up these oxidation states we get:

1 + 1 + (-6) + C = 0

-4 + C = 0

=> C = 4

This means the oxidation state of carbon in this compound is +4.