Answer:Water because it is an element
the answer is C
It is a chemical change because heat energy is absorbed and the pack gets colder. A change in temperature is a sign that a chemical reaction has taken place; increase in temperature is an exothermic reaction and decrease in temperature is an endothermic reaction. This is an endothermic chemical reaction.
Answer:
Red phosphorous can vary in colour from orange to purple, due to slight variations in its chemical structure. The third form, black phosphorous, is made under high pressure, looks like graphite and, like graphite, has the ability to conduct electricity.
Explanation:
Answer:
If you mean the number of atoms in 8g of oxygen, it's 3.011 x 10^23 atoms.
Explanation:
Convert the grams to moles. 8 grams of oxygen is 0.5 moles. Then multiply the number of moles by Avogadro's number: 6.022 x 10^23.