Chemistry MCQs
Topic Notes: Chemistry
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
The 2s-orbital of H-atom has a radial node at 2a0because $${\psi _{2s}}$$ is proportional to
Answer:
$$\left( {2 - \frac{r}{{{a_0}}}} \right)$$
Source answer preserved: option C ($$\left( {2 - \frac{r}{{{a_0}}}} \right)$$). AI attempted to change protected answer data (option_a, option_b, option_c, option_d), so this item is flagged for manual review before study use.
2
Quantum number values for 3p orbitals are____________________?
Answer:
n=3 l=1
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3
What is the atomic number of chlorine?
Answer:
17
The atomic number represents the number of protons in an atom's nucleus. Chlorine has 17 protons, defining its atomic identity.
4
What characteristic do isotopes of an element share?
Answer:
Chemical properties
Isotopes are atoms of the same element that have the same number of protons (atomic number) but differ in the number of neutrons. Despite these differences, they exhibit the same chemical properties due to the same electron configuration.
5
What does the sum of protons and neutrons in an atom represent?
Answer:
Both A and B
The sum of protons and neutrons in an atom is equal to both the nucleon number (total number of nucleons) and the mass number (total number of protons and neutrons).
6
Which element with the most unpaired electrons in its p-subshell has the highest atomic number?
Answer:
7
The element with the highest atomic number having maximum unpaired electrons in the p-subshell is Nitrogen (atomic number 7). It has three unpaired electrons in its 2p subshell.
7
The number of isotopes of elements with even mass number and even atomic number are ________________?
Answer:
154
This MCQ is about the number of isotopes for elements with even mass number (consisting of an even number of protons) and even atomic number (meaning they have an even number of protons). In such cases, the element has only one isotope, as its protons and neutrons are evenly distributed. Among the provided options, 154 is the correct answer, representing the number of isotopes for elements with these specific conditions.
8
In K2Cr2O7 the oxidation number of chromium is____________________?
Answer:
6
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9
The letters s, p, d, and f are used to represent which quantum numbers?
Answer:
Azimuthal
These letters represent the orbital angular momentum quantum number (l), which categorizes electron orbitals into different types. The letters 's', 'p', 'd', and 'f' correspond to l values of 0, 1, 2, and 3, respectively.
10
The one mole of _____molecule has the highest number of atoms?
Answer:
H2C2O4
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