Metalloids are compounds whose properties are intermediate between those of metals and non metals. That is, they do not behave as pure metals, neither do they behave as pure nonmetals. For instance, the electrical conductivity of metals decreases with temperature while nonmetals do not conduct electricity at all under any condition. However, metalloids conductivity increases with increase in temperature because they conduct electricity in a manner slightly different from the manner in which metals conduct electricity.
Boyle's law says "the pressure of a fixed amount of an ideal gas is inversely proportional to its volume when the temperature is constant".
P α 1/V
Where P is pressure of the gas and V is the volume of the gas.
Hence, we can use Boyle's law for two different situations as,
P₁V₁ = P₂V₂
P₁ = 100.0 kPa = 1 x 10⁵ Pa
V₁ = 3.3 L
P₂ = 90 x 10³ Pa
1 x 10⁵ Pa x 3.3 L = 90 x 10³ Pa x V₂
V₂ = 3.7 L
Hence, if the pressure drops from 100 kPa to 90 kPa, then the volume of the gas will be 3.7 L.
Here, we made an assumption as the gas is an ideal gas.
c) 2 mol of Kl in 500. g of water
Colligative properties such as melting and boiling points and osmotic pressure all depend on the amount of solute present. The more the concentration of solute present, the greater the degree of display of colligative properties by a solution
Considering the options given, 2 mol of Kl in 500. g of water has the highest concentration and is expected to freeze at the lowest temperature.
5. force and speed
Nuclear fusion in stars causes the hydrogen atoms to collide with each other and form the heavier helium atom. The fusion reaction is therefore:
₁H² + ₁H² → ₂He⁴
Extreme heat in the center of nebulae causes hydrogen atoms to shed their electrons and collide with one another. The force and speed of the collisions cause the smaller, bare nuclei to fuse into large helium nuclei.
All ancient fossils contain C-14
All living things contain more than one isotope of carbon, the most prominent being, carbon -12 and carbon-14.
Carbon-14 is a radioactive isotope of carbon. When the artifact is retrieved, the activity of carbon-14 in that sample is matched with the carbon-14 activity of a living organism. When this is done, the age of the fossil can easily be accurately calculated.