A mass of 135 g of an element is known to contain 30.1 1023 atoms. What is the element?
hydrogen
oxyden
aluminum
carbon
Is it aluminum?
Aluuminim
5- Consider Close packing of spheres as shown in figure.
a- What is the lattice corresponding to this arrangement?
b- What axes can be defined for this lattice?
c- What are the primitive axes?
d- How many spheres are there in a cell? Hint: add sphere fractions inside the cell.
To determine the element, we need to calculate the molar mass of the element using the formula:
Molar mass = Mass / Number of atoms
Given:
Mass = 135 g
Number of atoms = 30.1 x 10^23
Calculating the molar mass:
Molar mass = 135 g / (30.1 x 10^23) atoms
Dividing the mass by the number of atoms will give us the molar mass of the element. However, since the molar mass is typically expressed in grams per mole (g/mol), we need to convert the units. The Avogadro's constant (6.022 x 10^23) allows us to convert atoms to moles.
Molar mass = (135 g / (30.1 x 10^23) atoms) x (1 mol / 6.022 x 10^23 atoms)
Simplifying the expression:
Molar mass = (135 g x 1 mol) / (30.1 x 6.022 x 10^23)
Calculating:
Molar mass = 4.49 g/mol
Now that we have the molar mass, we can refer to the periodic table to determine the element with a molar mass of approximately 4.49 g/mol. In this case, the element is hydrogen, as its molar mass is very close to 4.49 g/mol.
So, the correct answer is hydrogen, not aluminum.