1 how many valence electrons does an atom of nitrogen have? 2 which of the following is a property of the…
1 how many valence electrons does an atom of nitrogen have? 2 which of the following is a property of the element boron? a. its a gas at room temperature. b. its radioactive. c. it has 1 valence electron. d. it has properties of metals and non - metals. 3 which of the following elements have properties most similar to magnesium? a. calcium b. silicon c. argon d. copper 4 whats similar about this block of elements? a. they belong to the same group. b. they have the same number of valence electrons. c. they belong to the same period. d. they are all metals.
Answer
1. How many valence electrons does an atom of nitrogen have?
Explanation:
Step1: Determine the electron configuration of nitrogen
Nitrogen has an atomic number of (7). The electron configuration is (1s^{2}2s^{2}2p^{3}).
Step2: Identify valence electrons
Valence electrons are in the outermost shell. For nitrogen, the outermost shell is the second shell ((n = 2)). The number of electrons in the (n=2) shell is (2 + 3=5).
Answer:
(5)
2. Which of the following is a property of the element boron?
Explanation:
Step1: Analyze option a
Boron is a solid at room temperature, so option a is incorrect.
Step2: Analyze option b
Boron is not radioactive (naturally - occurring boron is stable), so option b is incorrect.
Step3: Analyze option c
Boron has (3) valence electrons ((1s^{2}2s^{2}2p^{1})), so option c is incorrect.
Step4: Analyze option d
Boron is a metalloid, which has properties of metals and non - metals.
Answer:
d. It has properties of metals and non - metals.
3. Which of the following elements have properties most similar to Magnesium?
Explanation:
Step1: Recall the periodic table group concept
Elements in the same group (vertical column) of the periodic table have similar chemical properties. Magnesium ((Mg)) is in group (2) (alkaline earth metals).
Step2: Check each option
- Calcium ((Ca)) is also in group (2).
- Silicon ((Si)) is in group (14).
- Argon ((Ar)) is in group (18) (noble gases).
- Copper ((Cu)) is in group (11).
Answer:
A. calcium
4. What's similar about this block of elements?
Explanation:
Step1: Analyze the position of elements in the periodic table
The elements (B), (C), (N), (O), (F) are in the second period (horizontal row) of the periodic table.
- Option A: They are not in the same group.
- Option B: They do not have the same number of valence electrons ((B:3), (C:4), (N:5), (O:6), (F:7)).
- Option C: They are in the same period (period (2)).
- Option D: Boron is a metalloid, carbon and nitrogen are non - metals, oxygen and fluorine are non - metals.
Answer:
C. They belong to the same period.