1) Atomic number of argon (Ar) is 18, it means that it has 18 protons and 18 electrons.
Electron configuration of argon atom: ₁₈Ar 1s² 2s² 2p⁶ 3s² 3p⁶.
2) Atomic number of chlorine (Cl) is 17, it means that it has 17 electrons and 17 protons, but if it receive one electron, it becomes anion Cl⁻ with 18 electrons.
Electron configuration of chlorine anion: ₁₇Cl⁻ 1s² 2s² 2p⁶ 3s² 3p⁶.
3) Atomic number of sulfur (S) is 16, it means that it has 16 electrons and 16 protons, but if it receive two electrons, it becomes anion S²⁻ with 18 electrons.
Electron configuration of sulfur anion: ₁₆S²⁻ 1s² 2s² 2p⁶ 3s² 3p⁶.
Mass of MnO2 = 25 g
The reaction would be 3MnO2 + 4Al --> 3Mn(s) + 2Al2O3
Molar mass of Al = 26.982 g/mol
Molar mass of MnO2 = 54.938 + 2(15.999) = 86.936 g/mol
Calculating the moles = 25 / 86.936 = 0.2876 mol.
Mole ratio MnO2 and Al considering the equation = 3 mol of MnO : 4 mol of Al
Calculating the moles of Al = 0.2876 mol MnO2 x (4 mol of Al / 3 mol of MnO)
Number of moles of Al = 0.3834
Getting the mass in grams as asked = 0.3834 mol x 26.982 g/mol = 10.34 grams.
Answer: Antimony: Antimony is used to create firework glitter effects. Barium: Barium is used to create green colors in fireworks,
Explanation:
B:
Although there are almost 100 elements in nature, only six of them compose 99% of our body’s mass— carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus.
Answer:
True
Explanation:
Just like the Earth, half of the Moon is lit by the Sun while the other half is in darkness.
