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
1
Which state of matter consists of ionized gas with free-moving electrons and positive ions?
Answer:
Plasma
Plasma is often called the fourth state of matter. It is formed at very high temperatures where atoms are stripped of their electrons, resulting in a soup of ions and electrons that conducts electricity.
2
Which state of matter has neither a definite shape nor a definite volume?
Answer:
Gas
Gases expand to fill the shape and volume of whatever container they are in because the intermolecular forces between gas particles are negligible.
3
Which state of matter is characterized by having a definite shape and a definite volume?
Answer:
Solid
Solids have a definite shape and volume because their particles are closely packed in a fixed, regular pattern. The intermolecular forces are strong enough to keep the particles from moving past one another, allowing only for vibration around fixed positions.
4
Mendeleev's Periodic Table had some gaps; he predicted the existence of an element he called 'Eka-Aluminum', which was later discovered as:
Answer:
Gallium
Mendeleev predicted the properties of 'Eka-Aluminum' (below Aluminum). When Gallium was discovered in 1875, its properties matched his predictions almost perfectly, which validated his periodic table.
5
What is the name of the vertical columns in the periodic table?
Answer:
Groups
Vertical columns in the periodic table are called groups (or families). Elements in the same group have the same number of valence electrons and similar chemical properties.
6
What determines the identity of an element?
Answer:
The number of protons
The atomic number, which is the number of protons in the nucleus of an atom, uniquely identifies an element. No two different elements have the same number of protons.
7
Which microorganism causes 'Amoebic Dysentery', a condition resulting in intestinal inflammation and bloody diarrhea?
Answer:
A protozoan called Entamoeba histolytica
Amoebic dysentery is caused by Entamoeba histolytica, a parasitic protozoan. It is typically spread through the fecal-oral route, often by consuming food or water contaminated with the cysts of the parasite.
8
Which of the following diseases is NOT caused by a bacterium?
Answer:
Dengue Fever
Dengue Fever is a viral disease transmitted by Aedes mosquitoes. Cholera, TB, and Tetanus are all caused by different species of bacteria. This distinction is important because only the bacterial diseases can be treated with antibiotics.
9
Which of the following is a viral disease that can lead to permanent paralysis by attacking the nervous system?
Answer:
Poliomyelitis (Polio)
Polio is caused by the poliovirus. While many people have no symptoms, in a small percentage of cases, the virus enters the central nervous system and destroys motor neurons, leading to muscle weakness and permanent paralysis.
10
What is the general valence shell electron configuration of Group 17 elements?
Answer:
$ns^2 np^5$
Group 17 (Halogens) have 7 valence electrons. Their configuration is $ns^2 np^5$, meaning they need only one more electron to achieve a stable noble gas configuration, which explains their high reactivity as oxidizers.