It is B. Thank you later please and do good on the test!
Answer:
3.011 × 10²³ atoms of Al
Explanation:
Given data:
Number of moles of Al₂(SO₄)₃ = 0.25 mol
Number of atoms of Al = ?
Solution:
In one mole of Al₂(SO₄)₃ there are 2 moles of Al.
In 0.25 mol × 2 = 0.5 mol
1 mole of any substance contain 6.022 × 10²³ atoms.
In 0.5 moles of Al:
1 mole contain 6.022 × 10²³ atoms.
0.5 mol × 6.022 × 10²³ atoms/ 1 mol
3.011 × 10²³ atoms
First, you need to count copper mass in alloy.
Second, you have to make an equation an find x ( the copper mass must be added). The answer is: 13,5g pure copper
Answer:
See explanation
Explanation:
The periodic table shows the atomic number and mass number of each element.
We know that the atomic number shows;
- The number of protons in the nucleus of the atom
- The number of electrons in the neutral atom of the element.
So we obtain the number of protons and electrons by looking at the atomic number shown in the periodic table.
We also know that;
Mass number = Number of protons + number of neutrons
Since number of protons = atomic number of the atom
Number of neutrons = Mass number - atomic number
Hence we obtain the number of protons by subtracting the atomic number from the mass number given in the periodic table.
