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2. Magnesium has an atomic number of 12 . Which of the following statements is ...

Sep 17, 2024

Solution by Steps

Question 2: Magnesium has an atomic number of 12. Which of the following statements is true of a neutral magnesium atom?

step 1

A neutral magnesium atom has an atomic number of 12, which means it has 12 protons

step 2

Since it is neutral, it must also have 12 electrons to balance the positive charge of the protons

step 3

The number of neutrons can be calculated using the mass number, which for magnesium is typically around 24. Thus, neutrons = mass number - protons = 24 - 12 = 12

step 4

Therefore, the correct statement is: It has 12 protons, 12 electrons, and 12 neutrons

2 Answer

Key Concept

Atomic structure of elements

Explanation

A neutral atom has equal numbers of protons and electrons, and the number of neutrons can be found by subtracting the number of protons from the mass number.

--- Question 3: Which type of bond represents a weak chemical bond?

step 1

Among the options, hydrogen bonds are known to be weaker than ionic and covalent bonds

step 2

Ionic bonds involve the transfer of electrons and are generally stronger, while covalent bonds involve sharing electrons

step 3

Therefore, the correct answer is hydrogen bond, as it is a type of weak chemical bond

3 Answer

Key Concept

Types of chemical bonds

Explanation

Hydrogen bonds are weak attractions between molecules, unlike ionic and covalent bonds which are much stronger.

--- Question 4: An isotope of sodium (Na) has a mass number of 22. How many neutrons does it have?

step 1

Sodium has an atomic number of 11, which means it has 11 protons

step 2

The number of neutrons can be calculated using the mass number: neutrons = mass number - protons = 22 - 11 = 11

step 3

Therefore, the correct answer is that the isotope has 11 neutrons

4 Answer

Key Concept

Isotopes and neutrons

Explanation

The number of neutrons in an isotope can be found by subtracting the number of protons (atomic number) from the mass number.

--- Question 5: Which of the following statements is not true?

step 1

All the statements provided are generally accepted facts about water

step 2

Water is indeed polar, stabilizes temperature, and is essential for life

step 3

However, the statement that water is the most abundant molecule in Earth's atmosphere is misleading, as water vapor is not the most abundant gas. The most abundant gas is nitrogen

step 4

Therefore, the correct answer is that the statement about water being the most abundant molecule in Earth's atmosphere is not true

5 Answer

Key Concept

Properties of water

Explanation

While water has many essential properties, it is not the most abundant molecule in the atmosphere; nitrogen holds that title.

--- Question 6: Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution?

step 1

A pH of 7 is considered neutral, while a pH above 7 indicates a basic solution

step 2

Since the pH is 8.0, it is slightly above neutral, indicating that the solution is weakly basic

step 3

Therefore, the correct answer is that the solution is weakly basic

6 Answer

Key Concept

pH scale and acidity/basicity

Explanation

The pH scale measures how acidic or basic a solution is, with values above 7 indicating basicity. A pH of 8.0 is considered weakly basic.