When an atomic nucleus emits an alpha particle it decay into an atom with atomic number 2 less and mass number 4 less. Thus Thorium 230 decay as follows.
230 90Th -------> 226 88Th + 4 2 He
thorium is in the atomic number 90 thus it during alpha decay it reduces to atomic number 88 while its 230 mass number reduces to 226
I think the correct answer from the choices listed above is option A. A refracting telescope is made smaller than a reflecting telescope because small lenses cause less distortion in images than big lenses. <span> They are not subject to chromatic aberration because reflected light does not disperse according to wavelength.</span>
1. This can be due to the dissolving of the solid in liquid and form a solution.
Dissolving is a physical property because dissolving doesn't form new substances and the chemical composition of the solid is not changed.
The color building up over the time can be due to the rate of dissolving of the solid and amount of particles have been dissolved.
Example:
- Dissolving of CuSO₄ solid in water.
- This develops a blue color.
2. This can be due to the chemical reaction between the solid and liquid.
Chemical reaction is a chemical property because from reacting substances new substances can be formed which the chemical formula is different from initial substances.
The color building up over the time can be due to the rate of the reaction and the amount of reactants.
Example:
- The reaction between calcium metal with water.
- The color of Ca(OH)₂ is white color.
- Reaction is
Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g)
Answer:
Given : No. Of moles = 1.5
To calculate : no. Of molecules =N
We know that moles = N / 6.022 x 10²³
Therefore, 1.5 x 6.022 x 10²³ = N
Hence N = 9.0330x 10²³ molecules
Answer: Honey has a much lower vapor pressure than pure water has. So, pure water evaporates at a much higher rate.
Explanation: