They're not important when solving math problems in class because you need to get the correct and accurate answers hence don't need to change them into significant figures
Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
Answer:The surface heated air expands as it warms, becomes less dense than surrounding cooler air and rises as buoyant and turbulent bubbles. This is convection and is the main process by which the troposphere mixes and heats. Although convection stirs and mixes the troposphere, the higher it is the colder it becomes.
Explanation: Read this and you'll get your answer~! I hope i helped you~! Have an GREAT day too~! <\3
Answer:The correct answer is option (C).
Explanation:

After the reaction between Zinc and copper(II) chloride, Zinc chloride and copper will be obtained as a product. This reaction occurs because zinc is more reactive than copper which displaces the copper from its aqueous solution.
The student will expect to find copper metal at bottom of the beaker with aqueous solution of zinc chloride.
Hence the correct answer is option (C).