Scientists use as chemical symbols.

The periodic table, which consists of 109 elements, that we know of, it was existing still before we got the systematic method. Jons Jacob Berzelius assigned these elements in place. The symbols always consist of 1 or 2 letters, first one is capital, and the 2nd one, (if its there) is always lowercase.

Short  Periodic Table

Hope i helped.

    5.5 n======    assuming that      we have      m = 0.145 kg    a = 38 m/s²therefore    5.51 n, but two significant figures.final answer: 5.5 n