Answer:
x=4
Explanation:
distribute-
2x+15x-21=47
combine like terms-
17x-21=47
add 21 to both sides
17x=68
Divide 17 from both sides
x=4
Answer:
Group 1A
Explanation:
The Alkali metals all end is S1. What period the element is in determines the 1st number. Example: : H ends 1s1
Answer:
See attached image
Explanation:
I highly recommend doing these yourself. They are very easy. Just move the decimal and add zeros according to the prefixes. The attached chart should help you know how many zeros to add, and where.
Well, in an atom, there are an equal number of protons and electrons so they cancel each other out.