How many atoms are in 49.6 g Se?

3.79 ×10²³ atoms

Explanation:

Given data:

Mass of Se = 49.6 g

Number of atoms = ?

Solution:

Formula:

Number of moles = mass/ molar mass

Molar mass of selenium is 78.96 g/mol.

by putting values,

Number of  moles = 49.6 g/ 78.96 g/mol.

Number of moles = 0.63 mol

Number of atoms:

Now we will apply Avogadro number.

1 mole contain 6.022×10²³ atoms

0.63 mol ×  6.022×10²³ atoms / 1 mol

3.79 ×10²³ atoms

question: ray weighs 100 kilograms, his wrestling partner, bobby, weighs 50 kilograms. if ray moves at 4 m s , how fast will bobby have to run at him to apply an equal amount of kinetic energy?

answer: 8 m/s he needs to run twice as fast to keep up so he has some work to do

explanation:   if the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

question answered by

(jacemorris04)