GATE Questions

---

An atom is the smallest particle of a substance. Chemical substances are divided into two major groups. They are

1. Pure Substances (and)

2. Mixtures.

There are two types of pure substances that are Elements and Compounds.

Elements : An element is a substance that is made up of only one kind of atoms and cannot be broken down into simpler substances by chemical means. Metals and Non- metals come under elements.

Examples of elements are Iron, Silver, Gold, Mercury etc.

Compounds : A Compound is a substance that is formed when two or more elements combine chemically.

Examples of compounds are Water, Carbon dioxide, methane, vinegar etc.

Mixtures : A Mixture is formed when two or more substances mixed together but not chemically combined.

Example: Air.

Ribosomes are present in prokaryotic cells. These are organelles which consist of two subunits. They are present in both Eukaryotic and Prokaryotic cells. They are made up of RNA and proteins and present in the cytoplasm and on the membranes and are involved in protein synthesis.

Living organisms often contain trace amounts of several elements, but the most abundant ones are oxygen, carbon, hydrogen, nitrogen, calcium, sulphur and phosphorus.

A person who pretends to be what he is not is an Imposter.

The micronutrients (or trace minerals): boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni). and cobalt (Co).

Our atmosphere is made up of

78% Nitrogen,

21% Oxygen and

1% all other gases like argon, carbon dioxide, neon, and helium.

So, Nitrogen makes up the majority of our atmosphere.

Magnetism in materials is due to circular motion of electrons.