Science MCQs

Practice multiple choice questions with instant feedback. Select an option to see if you're correct.

Total Questions
2100
Page 56 of 210
Question 551 Hard

Which of the following elements is a noble gas?

A
Nitrogen (N)
B
Oxygen (O)
C
Fluorine (F)
D
Neon (Ne)
Question 552 Hard

How many valence electrons does Nitrogen (Z=7) have?

A
2
B
5
C
7
D
8
Question 553 Hard

What is the main difference between the isotopes of an element?

A
Number of protons
B
Number of electrons
C
Number of neutrons
D
Number of shells
Question 554 Hard

What is the electronic configuration of Calcium (Atomic Number = 20)?

A
2,8,8,2
B
2,8,10
C
2,8,8,1,1
D
2,8,9
Question 555 Hard

An element has 3 shells and 2 electrons in its outermost shell. What is its atomic number?

A
12
B
13
C
14
D
20
Question 556 Hard

Which of the following elements has a valency of 3?

A
Boron (Z=5)
B
Nitrogen (Z=7)
C
Aluminum (Z=13)
D
All of the above
Question 557 Hard

How many periods contain 8 elements?

A
1
B
2
C
3
D
Both b & c
Question 558 Hard

The element with the smallest atomic number in Period 3 is:

A
Sodium (11)
B
Magnesium (12)
C
Aluminum (13)
D
Argon (18)
Question 559 Hard

What is the mass number of the most common isotope of carbon?

A
6
B
12
C
13
D
14
Question 560 Hard

How many electrons are needed for the M shell (n=3) to be completely filled?

A
2
B
8
C
10
D
18
Showing 551-560 of 2100 questions

Quick Stats

Total Questions 10900
easy 5797
medium 2983
hard 2120

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