Help pls Round the following number to 2 signifigant digits:
1.9999
You may need to use scientific notation.

Monkeys and bats have similar bone structure in their forelimbs. however, monkeys have longer forelimbs to use for climbing and swinging in trees. bats have shorter forelimbs to use for flight. which term best describes how monkey and bat forelimbs are related to each other? a. homologous b. embryonic c. analogous d. vestigial

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?