Questions

A Shrimps heart is located on its head.

This difference proves that the earth is flattened at the poles and is thus, not a perfect sphere. The shape is reffered to as "geoid"

In the above given sentences, only option C) The hen has laid 10 eggs is gramatically correct.

A) Not correct - We had gone to the party last night

Correct - We went to the party last night

B) Not correct - I have seen him yesterday

Correct - I saw him yesterday (We do not use the present perfect tense with past time expressions.)

D) Not correct - She is sleeping for 2 hours

Correct - She has been sleeping for two hours. (We use the present perfect continuous tense to show duration.)

Sukhna Lake is in Chandigarh, India.

It is a reservoir at the foothills of the Himalayas. It covers an area of 3 km². This rainfed lake was created in 1958 by damming the Sukhna Choe, a seasonal stream coming down from the Shivalik Hills.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

Fuse Wire is Made of an alloy of Tin and Lead.

If too high a current flows, the element rises to a higher temperature and either directly melts, or else melts a soldered joint within the fuse, opening the circuit. Thefuse element is made of an alloy of Tin and Lead to provide stable and predictable characteristics.