<span>A compound is ''composed'' of elements. The periodic table is made up of elements. Atoms makes up elements and elements when reacted together make compounds.
Na+ and Cl- makes NACL....salt. a compound</span>
The answer is theory because it says if and that means theory
5.05 + 5 + 5.1 = 15.15cm Then you just divide it by the amount of measurements you had like this:15.15 ÷ 3 = 5.04999971cm Then you can just round it to the 3rd figure: 5.05cm < And that's the mean/average length of the bar. :) (Or the one above if you want all of the decimals too)
C. Spacecraft are built to be airtight.
The electron bit would be 2 and you could colour in 4 boxes:) I had the same question as this and I got it correct
