Science All General Science Aptitude

The correct answer is D. Energy.
According to the law of conservation of energy, energy cannot be created or destroyed; it can only be transformed from one form to another or transferred from one object to another.

Mass divided by volume represents density.

Therefore, the correct answer is C. Density.

The most suitable method to separate a mixture of sand and salt is C. Dissolving salt in water and then filtration.

This process involves dissolving the salt in water, which will leave behind the sand. After the salt dissolves, the mixture can be filtered. The sand will remain in the filter while the salt solution passes through, effectively separating the two components.

Among the options provided, the element with both low density and a low melting point is A. Na (Sodium). Sodium has a relatively low density and a comparatively low melting point compared to the other elements listed.

The electronic configuration given as 2, 8, 2 corresponds to the element with an atomic number of 12. This configuration belongs to magnesium (Mg).

In the Modern Periodic Table, elements are arranged based on their electronic configurations and properties. For the configuration 2, 8, 2, the element falls in period 3 of the periodic table.

Therefore, the correct answer is D. Period 3.

1 joule per second (J/s) is equivalent to 1 watt (W). 

Therefore, the correct answer is C. 1 watt.

The modern periodic table is based on A. atomic number. The arrangement of elements in the modern periodic table is primarily based on their increasing atomic number, which represents the number of protons in the nucleus of an atom.

Given,
the mass of the body, m = 50 kg.
h is the height, t is the time.
g is the acceleration due to gravity which is aproximated to 10 m/s2 ?
h = 45 × 14 = 630 cm = 6.30 m ?
t = 10 s, g = 10 ms-2 ?

Potential Energy = mgh = 50 × 10 × 6.30 = 3150 J.
Power = PE / time = Energy / time
= 3150 / 10 = 315 watt. 

Among the options provided, Ammonium chloride (Option A) is the compound that can undergo sublimation. Sublimation is the process where a substance transitions from a solid directly to a gas without passing through the liquid state. Ammonium chloride is known to undergo sublimation under certain conditions of temperature and pressure.

The formula for kinetic energy (\(KE\)) is:

\[KE = \dfrac{1}{2} \times \text{mass} \times \text{velocity}^2\]

Given:
Mass (\(m\)) = 13 kg
Velocity (\(v\)) = 5 m/s

\[KE = \dfrac{1}{2} \times 13 \, \text{kg} \times (5 \, \text{m/s})^2\]\[KE = \dfrac{1}{2} \times 13 \times 25\]\[KE = \dfrac{325}{2}\]\[KE = 162.5 \, \text{J}\]

Therefore, the kinetic energy possessed by the object is 162.5 joules, which corresponds to option C.