Answer: Option (4) is the correct answer.
Explanation:
A mixture is defined as a substance that contains two or more different substance that are physically mixed with each other.
If solute particles are evenly distributed in a solvent then it is known as a homogeneous mixture.
For example, salt dissolved in water is a homogeneous mixture.
If solute particles are unevenly distributed into the solvent then it is known as a heterogeneous mixture.
For example, sand in water is a heterogeneous mixture.
Thus, we can conclude that the statement a mixture must contain at least two different substances, is correct about mixtures.
Answer:
For O: atomic number = 8 # neutrons = 8
For Al: atomic mass = 27, # electrons = 13
Answer:
Periodic but not oscillatory
Explanation:
The Orbital motion of the earth around the sun is not an oscillatory motion as it is not a two and Fro motion about a mean position. But it is a periodic motion.
Based on Heisenberg's uncertainty principle, the position and velocity of a particle cannot be determined simultaneously with accuracy.
In other words, Heisenberg's uncertainty principle states that the more accurately we know the position of a particle the less accurately we can know its velocity. Mathematically it is given as:
Δx.mΔv >= h/2π
where: Δx = uncertainty in position
m = mass
Δv = uncertainty in velocity
h = plancks constant
