Riley is scootering down the street before they come to a stop at a stop sign. They were traveling for 16 seconds at an acceleration of -2 m/s2.
What is their initial velocity?*

just subrracted them and find out whats m

Explanation:

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

1.solid

2.carbon dioxide

3.helium