1) B, Not 100% sure though
2)Building a rocket is a physical change technically its not changing its composition its just changing its appearance, the fuel for it causes a chemical change, there is an answer that is more clear, Grinding chalk into a fine powder only changes its shape which is a physical change.
Answer:
There are 2.258 x 10^24 molecules of CO2 in 165 grams of CO2.
Explanation:
First you have to calculate the molar mass of carbon dioxide ⇒ 44 grs/mol. Then,
44 grs ------------- 1 mol CO2
165 grs ------------ x = 3.75 moles of CO2.
Then, from Avogadros constant we have that there are 6.022 x 10^23 molecules in 1 mol. So,
1 mol CO2 ---------------- 6.022 x 10^23 molecules CO2
3.75 moles CO2-------- x = 2.258 x 10^24 molecules CO2.
There are 2.258 x 10^24 molecules CO2 in 165 grams of CO2.
A result of the common ion effect is that the selective precipitation of a metal ion, such as Ag+, is promoted by the addition of an appropriate counter ion (X-) that produces a compound (AgX) with a very low solubility.
Answer:
Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate). Crystals, in general, are pure substances. Tin, sulfur, and diamond are examples of pure substances that are chemical elements. All elements are pure substances
Explanation:
