Chemistry Questions

Electronegativity refers to the ability of an atom to attract shared electrons in a covalent bond. The higher the value of the electronegativity, the more strongly that element attracts the shared electrons.

Electronegativity increases from bottom to top in groups, and increases from left to right across periods. Thus, fluorine is the most electronegative element and lithium is the least.

A substance that cannot be decomposed (broken down) into simpler substances by ordinary chemical means.

Examples: gold, iron, carbon, hydrogen, oxygen, nitrogen.

Material composed of only one kind of matter throughout (same atoms or same molecules).

Jello is a colloid, a semi-rigid structure i.e, semi-solid suspended in a liquid. When you Heat it up a bit and you'll break the protein bonds of the gelatin and it will liquefy completely and if you freeze, it becomes solid.

The number of bonds between a pair of atoms is called the bond order.

Bond orders can be calculated from Lewis structures, which are the heart of the valence-bond model. Oxygen, for example, has a bond order of two.

When there is more than one Lewis structure for a molecule, the bond order is an average of these structures. The bond order in sulfur dioxide, for example, is 1.5  the average of an S-O single bond in one Lewis structure and an S=O double bond in the other.

In molecular orbital theory, we calculate bond orders by assuming that two electrons in a bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O₂ molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in antibonding molecular orbitals in the electron configuration of this molecule. Thus, the bond order is two.

The gram formula mass of a compound is nothing but the molar mass.

The molar mass of K2CO3 (Potassium Carbonate) is given by

Atomic weights of individual elements are

K (Potassium) = 39 g

C (Carbon) = 12 g

O (Oxygen) = 16 g

Hence, that of K2CO3 = 39(2) + 12 + 16(3)

= 78 + 12 + 48

= 138.

Vitamins are essential nutrients found in foods. They perform specific and vital functions in a variety of body systems, and are crucial for maintaining optimal health.

The two different types of vitamins are fat-soluble vitamins and water-soluble vitamins.

Fat-soluble vitamins :

 Vitamins A, D, E and K — dissolve in fat before they are absorbed in the bloodstream to carry out their functions. Excesses of these vitamins are stored in the liver, and are not needed every day in the diet.

Water-soluble vitamins :

Vitamins dissolve in water and are not stored by the body. Since they are eliminated in urine, we require a continuous daily supply in our diet. The water-soluble vitamins include the vitamin B-complex group and vitamin C.

Water-soluble vitamins are easily destroyed or washed out during food storage or preparation.