Answer:
Phosphorus, Sulfur, and Selenium are the only <u>poly</u>atomic elements.
Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine, and Iodide are all <u>di</u>atomic elements.
Answer:
How to differentiate between physical and chemical change?
Physical and Chemical Changes to Matter
Physical changes only change the appearance of a substance, not its chemical composition.
Chemical changes cause a substance to change into an entire substance with a new chemical formula.
Chemical changes are also known as chemical reactions.
Answer: 3.57 moles
Explanation: 1mole of NO contains 22.4L at stp.
Xmol of NO wiil contain 80L i.e
Xmol of NO = 80/22.4 = 3.57 moles