Volume = a x a x a
V = 2 cm x 3 cm x 4 cm => 24 cm³
Density = 19.3 g/cm³
Mass = ?
Therefore:
m = D x V
m = 19.3 x 24
m = 463.2 g
Answer:
4
Explanation:
Relationship between wavenumber and Rydberg constant (R) is as follows:
Here, Z is atomic number.
R=109677 cm^-1
Wavenumber is related with wavelength as follows:
wavenumber = 1/wavelength
wavelength = 253.4 nm
Z fro Be = 4
Therefore, the principal quantum number corresponding to the given emission is 4.
Answer:
B. They can for covalent bonds with other atoms.
Explanation:
Carbon = King of the elements on the periodic table
For its proclivity to form stable covalent bonds with multivalent atoms.
Empirical formula is the simplest ratio of components making up a compound.
The percentage composition of each element has been given
therefore the mass present of each element in 100 g of compound is
B N H
mass 40.28 g 52.20 g 7.53 g
number of moles
40.28 g / 11 g/mol 52.20 g / 14 g/mol 7.53 g / 1 g/mol
= 3.662 mol = 3.729 mol = 7.53 mol
divide the number of moles by the least number of moles, that is 3.662
3.662 / 3.662 3.729 / 3.662 7.53 / 3.662
= 1.000 = 1.018 = 2.056
the ratio of the elements after rounding off to the nearest whole number is
B : N : H = 1 : 1 : 2
therefore empirical formula for the compound is B₁N₁H₂
that can be written as BNH₂
