Water is H2O but I'm not sure about solids.
Answer:
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.
Answer:
Na
Explanation:
When identifying elements, you only need to look at the number of protons. Elements can have varying numbers of electrons and neutrons, but they can only have one number of protons.
Looking at the periodic table, the elements with 11 protons is sodium (Na).