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:
decreases
Explanation:
Gravirational force is directly proportional to the mass and inversely proportional to the distance.(Newton's law of gravitation)
Answer:
5.67x10²³ ions
Explanation:
By looking at the molecular formula, we can tell that there are three Sr²⁺ ions per Sr₃(PO₄)₂ molecule.
We <u>convert Sr₃(PO₄)₂ moles into Sr₃(PO₄)₂ molecules</u> by using<em> Avogadro's number</em>:
- 0.314 moles * 6.023x10²³ = 1.89x10²³ molecules
Finally we <u>multiply that number by 3</u> in order to <em>convert Sr₃(PO₄)₂ molecules to Sr²⁺ ions</em>:
- 1.89x10²³ * 3 = 5.67x10²³ ions.
Single displacement is the type of chemical reaction
Answer:
- 40.66
- 9.91
Explanation:
For the first question:
Our theoretical compound is MR₂
1 mol of MR₂ contains 1 mol of M and 2 moles of R
Let's find out the molar mass:
9.45 g/mol + 18.12 g/mol . 2 = 45.69 g/mol
We can solve this, by an easy rule of three:
1 mol of MR₂ weighs 45.69 grams
Then, 0.89 moles may weigh 40.66 g
For the second question:
Our theoretical compound is D₂G
Let's determine the molar mass:
11.45 g/mol . 2 + 44.57 g/mol = 67.47 g/mol
1 mol of anything contains 6.02×10²³ molecules. By this definition we can say that 6.02×10²³ molecules weigh 67.47 grams. Let's solve by the rule of three:
6.02×10²³ molecules weigh 67.47 g
8.84×10²² molecules may weigh (8.84×10²² . 67.47 ) / 6.02×10²³ = 9.91 g
