A student looks up an element on the periodic table. The table says that the atomic number of the element is 12 and the mass number of the element is 40. What information do these two numbers convey about the element?

Question

a
The element has 40 protons and 12 neutrons
b
The element has 12 protons and 12 neutrons
c
The element has 12 protons and has 28 neutrons
d
The element has 28 protons and 40 neutrons
Question 2
How many maximum electrons can fit in the second energy level of an atom?

a
8
b
2
c
4
d
6
Question 3
In order for an atom to be considered "neutral", which of the following must be true?

a
The number of protons and neutrons must be the same
b
The number of protons and electrons must be the same
c
There are more protons than electrons
d
There are more neutrons than protons
Question 4
The chemical formula of table salt, NaCl, tells us what about the atomic bonding of this molecule?

a
The Sodium (Na) has to be present before the Chlorine (Cl)
b
The structure of the Sodium (Na) and the Chlorine (Cl) is a triangle
c
Exactly 1 atom of Sodium (Na) is bonded with 1 atom of Chlorine (Cl)
d
Nothing can be determined without a visual guide first
Question 5
In all elements in a group, the thing that is the same is the:

a
Number of electrons in the valence shell
b
Number of electrons
c
Number of protons
d
Number of neutrons

Answer 1

Here are the answers to your questions:

Question 1: A student looks up an element on the periodic table. The table says that the atomic number of the element is 12 and the mass number of the element is 40. What information do these two numbers convey about the element?

• Answer: c The element has 12 protons and has 28 neutrons.
  Explanation: The atomic number (12) tells us the number of protons, and the mass number (40) is the sum of protons and neutrons. Therefore, the number of neutrons can be calculated as follows: \( \text{mass number} - \text{atomic number} = 40 - 12 = 28 \).

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Question 2: How many maximum electrons can fit in the second energy level of an atom?

• Answer: a 8
  Explanation: The maximum capacity of electrons in the second energy level is determined by the formula \( 2n^2 \), where \( n \) is the energy level number. For the second energy level (n=2), \( 2(2^2) = 2(4) = 8 \).

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Question 3: In order for an atom to be considered "neutral", which of the following must be true?

• Answer: b The number of protons and electrons must be the same.
  Explanation: An atom is neutral when it has an equal number of protons (positively charged) and electrons (negatively charged), which balance each other out.

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Question 4: The chemical formula of table salt, NaCl, tells us what about the atomic bonding of this molecule?

• Answer: c Exactly 1 atom of Sodium (Na) is bonded with 1 atom of Chlorine (Cl).
  Explanation: The formula NaCl indicates a 1:1 ratio of sodium to chlorine in the compound.

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Question 5: In all elements in a group, the thing that is the same is the:

• Answer: a Number of electrons in the valence shell.
  Explanation: Elements in the same group of the periodic table have the same number of valence electrons, which is responsible for their similar chemical properties.