Avoid These Highly Acidic Foods. 1  All meats such as pork, fish, seafood and poultry. 2  Dairy and eggs. 3  Grains and some legumes. 4  Artificial sweeteners, alcohol products, sugar, carbonated soft drinks. 5  Cigarettes and tobacco, coffee, black tea.
In more general terms specific gravity is the ratio of the density of a material to that of any standard substance, although usually this is water at 4 degrees Celsius or 39.2 degrees Fahrenheit. By definition, water has a density of 1 kg per litre at this temperature. The specific gravities of gases usually are compared to dry air which generally has a density of 1.29 g per litre. The specific gravity of all other materials is compared to water as a fraction heavier lighter or heavier density.
The specific gravity is the ratio between the density of an object, and a reference substance. Usually, our reference substance is water. The specific gravity can tell us, based on its value, if the object will sink or float in our reference substance.