Answer:
A. The lens spreads light.
Explanation:
The convex lens will converge the light that passes through it. The direction of light will be bend to be closer to the middle point. This is the lens used for the eyeglass that treat people with hypermetropia. That is why the convex lens also called a converging lens or a plus lens. The strength of the convex lens depends on its focal length, index of the material used, and the radius of curvature.
Answer:
Si₁₄ = 1s² 2s² 2p⁶ 3s² 3p²
Explanation:
Silicon is present in group 14 of periodic table.
It is blue-gray color metalloid.
Its atomic mass is 28 g/mol.
It is mostly used to make allow.
The most important alloy are Al-Si and Fe-Si. These are used to make different machine tools, transformer plates, engine etc.
Its atomic number is 14 and electronic configuration can be written as,
Electronic configuration:
Si₁₄ = 1s² 2s² 2p⁶ 3s² 3p²
The noble gas electronic configuration or abbreviated electronic configuration can also be written.
Si₁₄ = [Ne] 3s² 3p²
The atomic number of neon is 10. Its electronic configuration is,
Ne₁₀ = 1s² 2s² 2p⁶
That's why we write [Ne] for 1s² 2s² 2p⁶ in abbreviated electronic configuration of Si.
Answer:
Chemical Classification Carbonate
Explanation:
Answer:
Percent yield = 86.2%
Explanation:
Given data:
Mass of zinc = 3.68 g
Mass of zinc chloride = ?
Percent yield = ?
Actual yield = 7.12 g
Solution:
Chemical equation:
Zn + 2HCl → ZnCl₂ + H₂
Number of moles of zinc:
Number of moles = Mass /molar mass
Number of moles = 3.68 g / 65.38 g/mol
Number of moles = 0.06 mol
Now we will compare the moles of ZnCl₂ with zinc.
Zn : ZnCl₂
1 : 1
0.06 : 0.06
Theoretical yield of zinc chloride:
Mass of ZnCl₂ = moles × molar mass
Mass of ZnCl₂ = 0.06 mol × 136.286 g/mol
Mass of ZnCl₂ = 8.2 g
Percent yield:
Percent yield = actual yield / theoretical yield × 100
Percent yield = 7.12 g/ 8.2 g × 100
Percent yield = 86.2%
