I believe it is the first one
<span>The periodic table is the most important chemistry reference there is. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.
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Answer:D
Explanation:
It was right o khan academy
Answer:
5500000 millimeters
Explanation:
1 kilometre= 1000 meter
5.5 km=5.5 * 1000
=5500
Now,
1 metre = 1000 millimetres
5500 metre=1000*5500
=5500000 mm
