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.

The Wind is what has no voice but cries, no wings but flutters, toothless but bites, mouthless but mutters.

Cobalt therapy or cobalt-60 therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer.

Cobalt 60 is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. It is produced artificially in nuclear reactors.

Photosynthesis process removes carbon dioxide from the atmosphere. Green plants remove carbon dioxide from the atmosphere by photosynthesis. 

The level of carbon dioxide in the atmosphere is maintained by several processes, including photosynthesis, respiration and combustion. 

In general, polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes.
As water molecules are polar, polar molecules dissolves in water.

The digestion process starts in the mouth and the complete digestion process completes in the small intestine where all the nutrients in the food are absorbed.

1. Mutual exclusion (where at least one resource is non-sharable)

2. Hold and wait (where a process holds one resource and waits for other resource)

3. No preemption (where the resources can’t be preempted)

4. Circular wait (where p[i] is waiting for p[j] to release a resource. i= 1,2,…n

j=if (i!=n) then i+1

else 1 )