Provide the number of protons, electrons, and neutrons in the following neutral elements, isotopes, and ions. If the mass number isn't provided, use the mass number for the most common isotope of that element. 1. lodine-135

In the year 2005 , a picture supposedly painted by a famous artist some time after 1715 but before 1765 contains 97.6 percent of its carbon-14 (half-life 5730 years). From this information, could this picture have been painted by this artist? ? Approximately how old is the painting? \( \square \) years

\( \begin{array}{l}\text { Gas nitrogen dioksida }\left(\mathrm{NO}_{2}\right) \text { dapat membentuk gas } \\ \text { dinitrogen tetroksida }\left(\mathrm{N}_{2} \mathrm{O}_{4}\right) \text { dalam kesetimbangan } \\ \text { sebagai berikut: } \\ 2 \mathrm{NO}_{2}(\mathrm{~g})=\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \\ \text { Jika pada suatu suhu diketahui konsentrasi } \mathrm{NO}_{2}= \\ 0,2 \mathrm{M} \text { dan } \mathrm{N}_{2} \mathrm{O}_{4}=0,5 \mathrm{M} \text {, tentukan nilai konstanta } \\ \text { kesetimbangan } \mathrm{Kc} \text { untuk reaksi tersebut. }\end{array} \).

SECTION 3: Balance the following chemical reactions. a. \( \frac{\mathrm{Zn}}{\mathrm{Zinc}+\underset{\text { Hydrochloric Acid }}{\mathrm{HCl}} \rightarrow \underset{\mathrm{Zinc}}{\mathrm{ZnCl}}+\frac{\mathrm{H}_{2}}{\text { Chloride }}+\text { Hydrogen gas }} \)

4. How many atoms are found in a 15.3 g sample of bismuth? A. \( 1.26 \times 10^{26} \) atoms B. \( 4.41 \times 10^{22} \) atoms C. \( 6.02 \times 10^{23} \) atoms D. \( 9.21 \times 10^{24} \) atoms

How many mols are there in each of the following samples? (convert grams to mols) a. 42 grams of the radioactive isotope Carbon-14