Choose the appropriate question tag and fill in the blank.
Rockets carry satellites and people into space,
(A) doesn't they
(B) don't they
(C)
didn't they
(D) did they
the language func
Answers
Answer:
Rockets carry satellites and people into space, don't they?
(B) don't they is the correct answer.
Extra Information:
Question Tag =>
The question tag is a small addition to the end of the statement which changes it into a question.
Example =>
1. Well, we can’t jump over it, can we? [Positive Question Tag]
2. He certainly likes eating, doesn’t he? [Negative Question Tag}
These question tags are used in declarative sentences too and also to know whether the listener in the sentence agrees or disagrees with the speaker of the sentence.
Question tags can be both positive and negative.
Answer:
Answer:HYDROGEN
•Isotopes of hydrogen:
1. Protium H
2. Deuterium D
3. Tritium T
The difference in rate of reaction of these isotopes is due to the difference in atomic masses.
• Position of hydrogen:
At the same time hydrogen shows resemblances and differences with alkali metals and halogens. So hydrogen is seperately placed in the periodic table.
• Properties of hydrogen:
At standard temperature and pressure, hydrogen is a nontoxic, nonmetallic, odorless, tasteless, colorless, and highly combustible diatomic gas with the molecular formula H2.
• Laboratory preparation of hydrogen:
It can be prepared by the reaction of zinc with aqueous alkali.
Zn+2NaOH→ Na2ZnO2 + H2
•Industrial preparation of hydrogen:
It is prepared by coal gamification followed by water gas shift reaction.
°coal gasification_steam is passed over coke at 1270K to form water gas(mixture of CO and H2) Or syn gas.
°water gas shift reaction_syn gas is mixed with excess steam and passed over iron chromate at 673K to form a mixture of CO2 and H2
CO2 is removed by sodium arsenite solution.
•Uses of hydrogen:
1. In the manufacture of ammonia, methanol, and synthetic petrol.
2. In the hydrogenation of vegetable oil.
3. As rocket fuel
Explanation: