General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
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
31
The 'valence' of an atom refers to:
Answer:
The number of electrons in the outermost shell
Valence electrons are the electrons in the outermost shell of an atom. They determine the chemical reactivity and bonding capacity of the element.
32
Which of these diseases is characterized by the swelling of the parotid (salivary) glands?
Answer:
Mumps
Mumps is a viral infection that primarily affects the salivary glands located near the ears. This results in the characteristic 'puffy cheeks' and swollen jaw that are the hallmark symptoms of the disease.
33
According to the Kinetic Molecular Theory, the temperature of a gas is directly proportional to what?
Answer:
The average kinetic energy of the particles
Temperature is a measure of the average kinetic energy of the particles in a substance. As the temperature of a gas increases, the particles move faster, resulting in a higher average kinetic energy.
34
What is the main reason for 'food poisoning' after eating old or improperly stored food?
Answer:
Toxic substances produced by bacteria like Salmonella or Staphylococcus
Food poisoning is often caused by eating food contaminated with bacteria or the toxins they produce while growing on the food. Salmonella and Staphylococcus aureus are common culprits that cause vomiting and diarrhea shortly after ingestion.
35
Which of the following is a characteristic of noble gases?
Answer:
Full outer electron shells
Noble gases (Group 18) are very stable and unreactive because they have a complete valence shell (octet), meaning they have no tendency to gain or lose electrons.
36
Which bond is formed by the sharing of electron pairs between atoms?
Answer:
Covalent
Covalent bonding occurs between non-metal atoms that share one or more pairs of electrons to achieve a stable electron configuration (usually an octet).
37
Which model of the atom is often referred to as the 'Plum Pudding' model?
Answer:
Thomson Model
J.J. Thomson proposed that the atom was a sphere of positive charge with negatively charged electrons embedded in it, similar to raisins in a pudding. This was later disproved by Rutherford's gold foil experiment.
38
Common cold and COVID-19 are both respiratory infections. What is a shared characteristic of these diseases?
Answer:
They are both caused by viruses
Both the common cold (often caused by rhinoviruses) and COVID-19 (caused by the SARS-CoV-2 virus) are viral infections. Because they are viruses, they spread through droplets and do not respond to antibiotic treatment.
39
What is the maximum number of electrons that can occupy the first energy level (K-shell) of an atom?
Answer:
2
The maximum number of electrons in any shell is given by the formula $2n^2$, where $n$ is the shell number. For the first shell ($n=1$), the maximum is $2(1)^2 = 2$ electrons.
40
The nucleus of an atom consists of which particles?
Answer:
Protons and neutrons
The nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. These particles are collectively known as nucleons and are held together by the strong nuclear force.