Answer:
i) 24.305 u
iv) The number of protons determines an element's atomic number and is used to distinguish one element from another.
Explanation:
We have to find the number of molecules that are present in 0.54 g of Ca(NO₃)₂.
First we have to convert the mass of our sample into moles of Ca(NO₃)₂. We will use the molar mass of Ca(NO₃)₂ to do that.
molar mass of Ca = 40.08 g/mol
molar mass of N = 14.01 g/mol
molar mass of O = 16.00 g/mol
molar mass of Ca(NO₃)₂ = 1 * 40.08 g/mol + 2 * 14.01 g/mol + 6 * 16.00 g/mol
molar mass of Ca(NO₃)₂ = 164.10 g/mol
mass of Ca(NO₃)₂ = 0.54 g
moles of Ca(NO₃)₂ = 0.54 g * 1 mol/(164.10 g)
moles of Ca(NO₃)₂ = 0.00329 moles
According to Avogadro's number there are 6.022 *10^23 molecules in 1 mol of molecules. We can use that relationship to find the number of molecules that are present in our sample.
6.022 *10^23 molecules = 1 mol
molecules of Ca(NO₃)₂ = 0.00329 moles * 6.022 *10^23 molecules/(1 mol)
molecules of Ca(NO₃)₂ = 2.0 * 10^21 molecules
Answer: there are 2.0 * 10^21 molecules of Ca(NO₃)₂ in 0.54 g of it.
Answer:
element
A pure substance is matter that is uniform throughout and has consistent properties. All matter is made up of very small particles called atoms. Atoms are the building blocks of all matter. When a substance contains only one type of atom, it is called an element.
Answer:
4.99*10²³ molecules of N₂O₄ are in 76.3 g of N₂O₄
Explanation:
Avogadro's Number is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension. Avogadro's number applies to any substance.
You know that the molar mass of N₂O₄ is 92.02 g/mol, and you have 76.3 g. Then you can apply the following rule of three: 92.02 grams are present in 1 mole of the compound, 76.3 grams in how many moles are they?
amount of moles= 0.83 moles
Then, you can apply another rule of three: if by definition of Avogadro's number 1 mole of the compound has 6.023*10²³ molecules, 0.83 moles of the compound, how many molecules will it have?
amount of molecules= 4.99*10²³
<u><em>4.99*10²³ molecules of N₂O₄ are in 76.3 g of N₂O₄</em></u>
Gas are well separated with no regular arrangement<span>. liquid are close together and solid are right on-top of each other packed tightly</span>
