Answer:
b. primitive cubic < body-centered cubic < face-centered cubic
Explanation:
The coordination number is defined as <em>the number of atoms (or ions) surrounding an atom (or ion) in a crystal lattice</em>. Its value gives us a measure of how tightly the spheres are packed together. The larger the coordination number, the closer the spheres are to each other.
- In the <u>primitive cubic</u>, each sphere is in contact with 6 spheres, so its <u>coordination number is 6</u>.
- In the <u>body-centered cubic</u>, each sphere is in contact with 8 spheres, so its <u>coordination number is 12</u>.
- In the <u>face-centered cubic</u>, each sphere is in contact with 12 spheres, so its <u>coordination number is 12</u>.
Therefore, the increasing order in density is the primitive cubic first, then the body-centered cubic, and finally the face-centered cubic.
Answer:
B. a strongly basic solution
Explanation:
Kb is base dissociation constant, which indicates how completely a base dissociates into its component ions in water. The greater the Kb value, the greater the alkalinity of the solution and vice versa.
Therefore, a solution with a Kb value much greater than 1, indicates a strongly basic solution, while a solution with a Kb value less than 1, indicates a weakly basic solution.
Answer: B. The element called tin is a metal with the chemical symbol Sn.
Explanation:
A is incorrect because Ni is Nickel, not Niobium.
C is incorrect because Carbon is a nonmetal and its symbol is C, not Cr.
D is incorrect because Copper's symbol is Cu, not Ce.
E is incorrect because As is the symbol for Arsenic, not Astatine.
