Answer: Braces are used by the people to correct the alignment and position of tooth or teeth in the jaw.
Explanation:
The teeth braces must have strong tensile strength and must create a constant pressure on the teeth so as to allow the straightening of the teeth.
The strong force of attraction between the molecules of the braces material that can be steel, nickel, molybdenum, copper, titanium. This makes the bracing material rigid on the teeth.
Ground Water can become polluted from when fossils and things make their way to the bottom of the ground and polluted the ground water
The answer is either number one or two.
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