Curium is a hard, brittle, radioactive silvery metal. It does not occur in nature and must be made in a nuclear reactor by neutron capture reactions from plutonium and americium isotopes. It tarnishes slowly in dry air at room temperature.
Romaine lettuce is a rich source of fiber and has very few calories, only 8 in a one-cup serving. In terms of vitamins, a cup of Romaine lettuce delivers more than 50% of your daily requirement for vitamin A, as well as significant levels of vitamin K and vitamin C.
Research shows that darker âlooseâ or âopen leaf lettuces (such as romaine, red leaf, and butterhead) contain more antioxidants and nutrients than the typically lighter-colored, more tightly-packed heads (such as iceberg).nstead, a big, healthy salad is one of the smartest ways to go green. Coming in at under 10 calories per cup, a big bowl of leaves can be a stellar source of vitamins A, C, K, and folate, among other essential nutrients.