According to the U.S. mint the nickels currently in circulation weigh 5.000 grams and contain 25% Ni (the rest is copper).
25% of 5.000g = 1.250 grams of Ni in a nickel coin / molar mass of Ni 58.71 g/mol = 0.02129 moles of Ni times the number of particles for one mole 6.02x10^23 = 1.28x10^22 atoms of Ni in one coin.
All together:
(0.25 x 5.000g) / (58.71 g per mol) x (6.02x10^23 atoms per mol) = 1.28x10^22 atoms Ni per coin.
4 atoms per unit cell
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The atoms are located within the cell membrane.
Count the number of atoms that are all the way inside the cell. Each of these counts as 1. Count the number of atoms that are on a face, but not a corner or edge of the cell. Each of these count as 1/2. Count the number of atoms that are on an edge, but not a corner of the cell. Each of these count as 1/4. Count the number of atoms that are on a corner of the cell. Each of these count as 1/8. The final formula is: inside + 1/2 face + 1/4 edge +1/8 corner = total atoms per cell.
A FCC or Face Centered cubic unit cell has 4 atoms. It is calculated like this. There are 8 corners of the unit cell and each corner has one atom.But each atom is shared by 8 unit cells. So. total no. of atoms at corners= 1/8 *8=1 atom . Also, there are 6 faces which have one electron in the centre of it. Each such electron is shared between 2 unit cells. This gives the total no. of atoms at the centre of faces of unit cell=1/2 * 6 = 3 atoms. Adding the two, we get four atoms in an unit cell 1+3=4 atoms.
175.35 pm
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In a diamond unit cell, each carbon atom is located at the corners of the unit cell. Since there are eight corners in a unit cell, each shared by 8 adjacent unit cells, the contribution to the total number of carbon atoms is 1/8 of a carbon atom per unit cell. Therefore, there is 1 carbon atom per unit cell.
The atoms are located within the cell membrane.
Count the number of atoms that are all the way inside the cell. Each of these counts as 1. Count the number of atoms that are on a face, but not a corner or edge of the cell. Each of these count as 1/2. Count the number of atoms that are on an edge, but not a corner of the cell. Each of these count as 1/4. Count the number of atoms that are on a corner of the cell. Each of these count as 1/8. The final formula is: inside + 1/2 face + 1/4 edge +1/8 corner = total atoms per cell.
A FCC or Face Centered cubic unit cell has 4 atoms. It is calculated like this. There are 8 corners of the unit cell and each corner has one atom.But each atom is shared by 8 unit cells. So. total no. of atoms at corners= 1/8 *8=1 atom . Also, there are 6 faces which have one electron in the centre of it. Each such electron is shared between 2 unit cells. This gives the total no. of atoms at the centre of faces of unit cell=1/2 * 6 = 3 atoms. Adding the two, we get four atoms in an unit cell 1+3=4 atoms.
175.35 pm
Body centered is another cubic unit cell.This unit cell has atoms at the eight corners of a cube and one atom in the center. Once again, the corner atoms are bisected by three orthogonal the planes leaving one-eighth of each atom inside. The central atom is also inside, so this unit cell contains two atoms. Nickel is an example of a substance that has a body centered cubic crystal structure.
The smallest living unit is the cell, which is made up of molecules, which in turn is made up of atoms, but neither molecules nor atoms are alive.
You need to know the space group. Each space group specifies how many "objects" it contains. Multiply that by the number of atoms per molecule/formula unit and you're done.
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you subtract the atomic number by the number of atoms
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