Answer:
2/3
Explanation:
Crystals structures can also be seen when two elements combines together and the perfect example is Al₂O₃ which is given in the question above. Just like it is given in the question above, the kind of arrangement in the crystal structure for Al₂O₃ is called HCP which stands for Hexagonally Closed Pack.
The aluminum ions which is in form of Al³⁺ occupies the two-third[2/3] positions while the position that the oxygen ion occupies is one[1].
B: nothing the color of the solution when heated
There are types of lens; concave and convex lens.
The concave lens is a lens which has an inward curve in the middle, that is, the edges of the curve are thicker than the center of the lens, because of this, any light that enter the lens will spread out [diverge]. An image will look smaller and upright when viewed by a concave lens. Image formed by concave lens are usually VIRTUAL.
A concave lens will produce a real image ONLY if the object is located beyond the focal point of the lens.
A convex lens is a converging lens, this is because, the center of the lens is thicker than its edges. Any ray of light that passes through the lens will converge at the middle of the lens at point called principal focus. A convex lens produce a VIRTUAL image when the object is placed infront of the focal point. The virtual image formed is always magnified and upright.<span />
b. increase in surface area
<h3>Further explanation</h3>
Given
Speeding up a chemical reaction
Required
Factors used to speed up reactions
Solution
There are several factors that influence reaction kinetics :
1. Concentration
2. Surface area
3. Temperature
4. Catalyst
5. Pressure
6. Stirring
Temperature is related to the kinetic energy of the particles. Heat is absorbed causes the particles of matter to move faster so that the reaction can take place faster
The enlarged surface area of the reactants causes more particles to react with other particles.
50 g square block of sulfur can be broken into small pieces or powdered so that more particles come into contact with each other