20 points! the cdc (centers for disease control) is a federal agency that monitors the spreading of various diseases and health issues. they have done extensive research on the effects of tobacco on a person's health. the cdc does a study on smoking with the hypothesis, "if a person smokes more cigarrettes, then they are more likely to develop heart disease". which of the following should be a controlled variable for this experiment? choose all that apply. 1. amount of smoking a person does 2. weight class of the person 3. state where the person lives 4. whether or not the person develops heart disease

What is the ima of the 1 st class lever in the graphic given? 2 3 0.5

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Gusing the milligrams of ascorbic acid you entered above, the ratio of total sample volume to aliquot volume, and the total milligrams of the vitamin c tablet that you dissolved, calculate the mass of ascorbic acid in the vitamin c tablet for each trial. do this by scaling up to find the amount (mg) of ascorbic acid in your 250 ml flask. enter your calculated mass of ascorbic acid in the vitamin c tablet, for each trial. be sure to enter your calculated mass in the corresponding order that you entered your milligrams of ascorbic acid. the milligrams of ascorbic acid you entered for entry #1 previously should correspond to the mass of ascorbic acid that you enter for entry #1 here.