Question

question 11 (1 point)
(02.02 lc)
which of the following best describes a nonmetal?
a brittle, shiny, and solid at room temperature
b brittle, dull, and low density
c malleable, shiny, and able to conduct electricity
d malleable, dull, and solid, liquid, or gas at room temperature

question 12 (1 point)
(02.02 lc)
a student observes that an element is shiny, bends easily, and can conduct electricity. what type of element is the student most likely observing?
a gas
b metal
c metalloid
d nonmetal

question 13 (1 point)
(02.02 mc)
nickel has the chemical symbol ni and the atomic number 28. how many protons, neutrons, and electrons would be found in an atom of nickel - 78?
a 28 protons, 28 neutrons, 50 electrons
b 28 protons, 50 neutrons, 28 electrons
c 50 protons, 28 neutrons, 50 electrons
d 50 protons, 50 neutrons, 28 electrons

Explanation:

• Question 11: Non - metals are typically brittle, dull, and have low density. Option a is incorrect as non - metals are not usually shiny. Option c describes properties of metals (malleable, shiny, and good conductors). Option d has malleability which is a metallic property.
• Question 12: Shiny, bendable (malleable), and good electrical conductivity are properties of metals. Gases do not have these properties. Metalloids have intermediate properties and non - metals lack these metallic properties.
• Question 13: The atomic number (Z) is equal to the number of protons. For nickel, Z = 28, so there are 28 protons. In a neutral atom, the number of electrons is equal to the number of protons, so there are 28 electrons. The mass number (A) of nickel - 78 is 78. The number of neutrons (N) is calculated as N=A - Z. So, N = 78 - 28=50 neutrons.

Answer:

Question 11: B. Brittle, dull, and low density
Question 12: B. Metal
Question 13: B. 28 protons, 50 neutrons, 28 electrons