$$\(\alpha\text{-}\)particle consists of:

If an alpha nucleus of energy $\frac{1}{2}m{v}^2$ bombards a heavy nuclear target of charge Ze, then the distance of closest approach for the alpha nucleus will be proportional to:

If the nucleus ${}_{13}{}^{27}\mathrm{Al}$ has a nuclear radius of about 3.6 fermis, then ${}_{52}{}^{125}\mathrm{Te}$ would have its radius approximately as:

1. 6.0 Fermi

2. 9.6 Fermi

3. 12.0 Fermi

4. 4.8 Fermi

The radius of Germanium (Ge) nuclide is measured to be twice the radius of ${}_4{}^9\mathrm{Be}$. The number of nucleons in Ge is:

1. 73

2. 74

3. 75

4. 72

An electron is moving around the nucleus of a hydrogen atom in a circular orbit of radius r. What is the coulomb force $\overrightarrow{\mathrm{F}}$ between the two? \(\left ( \text{where},K=\frac{1}{4\pi \epsilon _{0}} \right )\)

1. $\mathrm{K}\frac{{\mathrm{e}}^2}{{\mathrm{r}}^2}\hat{\mathrm{r}}$

2. $-\mathrm{K}\frac{{\mathrm{e}}^2}{{\mathrm{r}}^3}\hat{\mathrm{r}}$

3. $\mathrm{K}\frac{{\mathrm{e}}^2}{{\mathrm{r}}^3}\overrightarrow{\mathrm{r}}$

4. $-\mathrm{K}\frac{{\mathrm{e}}^2}{{\mathrm{r}}^3}\overrightarrow{\mathrm{r}}$