Questions

The earliest historic evidences of use of metal are of Chalcolithic Age or Stone-Copper Age, which covered the period from 1800 - 800 BC. This period was by the use of Copper as well as stone.

Hence, the first metal to be used in India is Copper.

The number of blueberries is equal to number of cups multiplied by 4 minus one left.

That is :

      B = 9(C - 2) -> (1)

Then the number of blueberries will be equal to the number of cups times three plus one left.

That is :

      B = 6C + 3 -> (2)

Now substitute the 1st and 2nd equations:

      B = 9(C - 2)

      B = 6C + 3

      C = 7, B = 45.

Therefore Blueberries = 45 and cups = 7.

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.

Hemopoiesis begins in the red bone marrow, with hemopoietic stem cells that differentiate into myeloid and lymphoid lineages.

Myeloid stem cells give rise to all the other formed elements, including the erythrocytes; megakaryocytes that produce platelets; and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes: neutrophils, eosinophils, and basophils.