Correct Answer: C. copper (ll) tetraoxosulphate (VI) pentahydrate

Correct Answer: B. hands

Correct Answer: D. final image is at infinity

Explanation

An astronomical telescope is in normal adjustment when the final image is at infinity.

Here's why:

• When the final image is at infinity, the light rays entering the observer's eye are parallel.

• The human eye is most relaxed (unaccommodated) when viewing objects at infinity, as its ciliary muscles are relaxed. This makes viewing through the telescope more comfortable for extended periods.

• In this adjustment, the distance between the objective lens and the eyepiece is equal to the sum of their focal lengths (f_o + f_e). The intermediate image formed by the objective lens falls precisely at the focal point of the eyepiece.

Therefore, the correct answer is D.

Correct Answer: D. Pressure groups influence government policies to member's interest

Explanation

While a political party is a group of people who organize to win elections, operate the government, and determine public policy, pressure groups is a group of people who share common goals and who actively try to influence policymakers.

Correct Answer: B. sequentially, without overlapping

Correct Answer: B. $15.00

Correct Answer: C) diamond and graphite

Explanation

Allotropes are different forms of the same element in the same physical state, but with different properties due to variations in the arrangement of atoms. Carbon is an element with several allotropes, which include diamond, graphite, amorphous carbon, and fullerenes.

In this question, the correct answer isOption C: diamond and graphite. Both diamond and graphite are well-known allotropes of carbon, and they differ in their properties due to the arrangement of carbon atoms in their structures.

Diamond is a hard, crystalline form of carbon in which each carbon atom is covalently bonded to four other carbon atoms in a tetrahedral arrangement. This structure results in very strong bonds, making diamond the hardest naturally occurring substance known. Diamond is also an excellent thermal conductor and has a high refractive index, which contributes to its sparkle as a gemstone.

Graphite, on the other hand, is a soft, slippery form of carbon in which each carbon atom is covalently bonded to three other carbon atoms, forming hexagonal layers. These layers are held together by weak van der Waals forces, which allow the layers to slide past each other easily. This property makes graphite an effective lubricant and a good conductor of electricity.

It is worth mentioning that amorphous charcoal and coke, mentioned in Option B, are also forms of carbon, but they are not considered true allotropes because they do not have well-defined crystal structures like diamond and graphite.

Correct Answer: D. praying three times daily for thirty days

Correct Answer: B. Friend of God

Correct Answer: A. the unity of Allah