Carbon dioxide. Carbon dioxide (chemical formula CO2) is a colorless gas with a density about 60% higher than that of air (1.225 g/L) that is odorless at normally encountered concentrations. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms.
You should only do ballet in pregnancy if you are used to it. Ballet stretches can place a lot of pressure on your joints, especially your pelvic joints, and standing on one leg can cause pain in your pelvis.
1 You might not be able to do prenatal yoga if you are at increased risk of preterm labor or have certain medical conditions, such as heart disease or back problems.  Set realistic goals. For most pregnant women, at least 30 minutes of moderate physical activity is recommended on most, if not all, days of the week.