Scientists plan to place detection devices outside earth's atmosphere to detect radiations from a star. which of the following best explains the type of detection device that the scientists would use. a. a radar, because high frequency microwaves are limited to the region outside earth's atmosphereb. special cameras, because high frequency uv rays are emitted by objects at very high temperaturesc. special cameras, because high energy uv rays are emitted by objects having very high massd. a radar, because high energy microwaves are produced from very hot objects

the correct option is A (A radar, because high frequency microwaves are limited to the region outside Earth's atmosphere)

Explanation:

A radar can be used for detection of devices outside Earth's atmosphere to detect radiations from a star. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s) example the stars

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.