The Colorado River begins in West Texas and flows more
than 800 miles to Matagorda Bay at the Gulf of Mexico. As
the speed of the river decreases, which factor will likely
increase?

Pressure Increases.

Explanation:

Basically i did a bit of research and came across Bernoulli's principle, which basically says that as speed increases then pressure decreases, and vice versa.

Hope this helps and stay safe

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.