Explanation:
1. Electrons surround the nucleus in defined regions called orbits.
2. The shells further away from the nucleus are larger and can hold more electrons.
3. The shells closer to the nucleus are smaller and can hold less electrons.
4. The closest shell (closest to the nucleus) can hold a maximum of two electrons.
5. Once the first shell is full, the second shell begins to fill. It can hold a maximum of eight electrons.
6. Once the second shell is full, the third shell begins to fill.
7. Once the third shell contains Eighteen electrons, the fourth shell begins to fill.
8. The arrangement of electrons in shells around the nucleus is referred to as an atom's electronic configuration.
The atomic mass of an element on the periodic table is the weight of 1 mole of atoms. For example, the atomic mass of Fe is 55.8 on the periodic table. If you weigh out 55.8 grams of Fe you will have 1 mole of iron, or 6.02 x 1023 atoms.
Answer:
There are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.
Explanation:
We can calculate the number of moles (η) of BeO as follows:
Where:
m: is the mass = 250 g
M: is the molar mass = 25.0116 g/mol
Hence, the number of moles is:
Therefore, there are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.
I hope it helps you!
Answer:
The answer to your question is It will be formed 0.39 moles of H₂
Explanation:
Data
moles of H₂ = ?
moles of HCl = 0.78
moles of Zinc = excess
Balanced chemical reaction
2 HCl + Zn ⇒ 1 H₂ + ZnCl₂
Process
1.- Use proportions to solve this problem. Consider the coefficients of the balanced reaction.
2 moles of HCl ---------------------- 1 mol of H₂
0.78 moles of HCl ----------------- x
x = (0.78 x 1) / 2
- Simplification
x = 0.78 / 2
- Result
x = 0.39 moles of H₂
Answer:
correct option is A) atmospheric pollutants
Explanation:
- Nuclear power plant do not produce air pollution in the form of carbon dioxide and sulfur dioxide.
- Nuclear as radioactive waste is hazardous to all kind of life and the environment.
- Long-term storage of radioactive waste is required. It is important that waste stabilization is a form that does not react or deteriorate for years.
- If nuclear waste is wasted in the atmosphere or in the oceans and lagre lakes, it eventually comes into contact with organisms.
