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
101
Which of the following elements is a liquid at room temperature?
Answer:
Both B and C
Mercury (a metal) and Bromine (a non-metal) are the only two elements that are liquid at standard room temperature (25°C).
102
Which element has the highest electron affinity (most energy released)?
Answer:
Chlorine
Although Fluorine is more electronegative, Chlorine has the highest electron affinity. Fluorine is so small that its electrons repel the incoming electron more than in the slightly larger Chlorine atom.
103
The elements of Group 15 are collectively called:
Answer:
Pnictogens
Group 15 elements (Nitrogen family) are called pnictogens. The name comes from the Greek word 'pnigein', meaning 'to choke', referring to the properties of nitrogen gas.
104
What is the specific role of a 'vector' in the spread of diseases like Malaria or Dengue?
Answer:
It is an organism that carries and transmits a pathogen to another living being
A vector is an intermediary organism, often an arthropod like a mosquito or tick, that picks up a pathogen from one host and transmits it to another. In the case of Malaria, the female Anopheles mosquito acts as the vector for the Plasmodium parasite.
105
The 'shielding effect' (or screening effect) refers to:
Answer:
The repulsion of inner shell electrons on valence electrons
Inner shell electrons act as a 'shield' between the positive nucleus and the valence electrons, reducing the effective nuclear charge felt by the outermost electrons. This effect increases as the number of occupied inner shells increases down a group.
106
What is the relative mass of an electron compared to a proton?
Answer:
Approximately 1/1840
Electrons are much lighter than protons and neutrons. It takes about 1836 to 1840 electrons to equal the mass of a single proton.
107
Which of the following elements is a 'Noble Metal' due to its low reactivity?
Answer:
Gold
Noble metals (like Gold, Platinum, and Silver) are resistant to corrosion and oxidation in moist air, unlike base metals like Iron or Sodium.
108
Second ionization energy is always _______ than the first ionization energy.
Answer:
Greater
Removing a second electron requires pulling it away from a positively charged ion ($X^+$). The remaining electrons feel a stronger effective nuclear charge and are held more tightly, requiring significantly more energy.
109
Which of the following practices is the most effective way to prevent the transmission of many infectious diseases in daily life?
Answer:
Regular handwashing with soap and water
Handwashing is the single most effective way to remove pathogens from the hands before they can enter the body through the mouth, nose, or eyes, or be passed on to other people and surfaces.
110
Who discovered the neutron?
Answer:
James Chadwick
James Chadwick discovered the neutron in 1932. This discovery was crucial because it explained why the atomic mass of elements was often more than double their atomic number.