Answer:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds. ... The ratio of the elements in a compound are always constant. (Water is always 11 % Hydrogen and 89 % oxygen).
Explanation:
Answer: you have to be sure to cite evidence
Half reaction N_2 H_4 (aq) → N_2 (g)Balancing atoms except O and H N_2 H_4 (aq) → N_2 (g)Balancing charge N_2 H_4 (aq)→N_2 (g)+4H^+ (aq)Balanced half reaction for oxidation of hydrazine to gaseous nitrogen is N_2 H_4 (aq)→N_2 (g)+4 H^+ (aq)+ 4e^-
Answer:
Since the chemical composition of the substance stays the same, such as that of water in the above mentioned example, melting and boiling are physical changes. And hence, boiling points and melting points are physical properties. Since they are a property of the material, they can be used to identify it.
Explanation:
Eating, drinking...pretty sure
