Problem 29 - Chemistry: The Central Science

Question

Fill in the gaps in the following table, assuming each column represents a neutral atom. $$ \begin{array}{l|c|c|c|c|c} \hline \text { Symbol } & { }^{159} \mathrm{~Tb} & & & & \\ \text { Protons } & & 29 & & & 37 \\ \text { Neutrons } & & 34 & 53 & & \\ \text { Electrons } & & & 42 & 34 & \\ \text { Mass no. } & & & & 79 & 85 \\ \hline \end{array} $$

Step-by-Step Solution

Answer

}}\mathrm{Cu} & & {}^{\mathrm{?}}\mathrm{Se} & { }^{85} \mathrm{Rb} \\ \text { Protons } & 65 & 29 & & 34 & 37 \\ \text { Neutrons } & 94 & & 53 & & 48 \\ \text { Electrons } & 65 & 29 & 42 & 34 & 37 \\ \text { Mass no. } & 159 & & & & 85 \\ \hline \end{array} $$

Step 1: Identify the given information for each atom

The table has the following information given: $$ \begin{array}{l|c|c|c|c|c} \hline \text { Symbol } & { }^{159} \mathrm{Tb} & & & & \\ \text { Protons } & & 29 & & & 37 \\ \text { Neutrons } & & 34 & 53 & & \\ \text { Electrons } & & & 42 & 34 & \\ \text { Mass no. } & & & & 79 & 85 \\ \hline \end{array} $$ Next, we will fill the table by deriving the information for each atom using the relationships mentioned above.

Step 2: Derive the information for each atom using the relationships

Let's start with the first atom \({ }^{159}\mathrm{Tb}\): Number of protons (\(p\)): Tb is Terbium, which has 65 protons. Number of neutrons (\(n\)): Using the relationship \(A = p + n\), we get \(n = A - p = 159 - 65 = 94\). Number of electrons (\(e\)): In a neutral atom, the number of electrons equals the number of protons, so \(e = p = 65\). Moving on to the second atom with 29 protons: Symbol: The element with 29 protons is Copper (Cu). Number of neutrons (\(n\)): We do not have enough information to calculate this. Number of electrons (\(e\)): Since it is a neutral atom, e = p = 29. Mass number (\(A\)): We do not have enough information to calculate this. For the third atom with 53 neutrons: (Symbol, Number of protons, and Mass number: We do not have enough information to calculate these) Number of electrons (\(e\)): We have 42 electrons. Now for the fourth atom with 34 electrons: Symbol: Since we know (from Step 3) that atomic number = number of protons, we can conclude that this atom has 34 protons, which means it is Selenium (Se). Number of protons (\(p\)): Since it's a neutral atom, p = e = 34. Number of neutrons (\(n\)): We do not have enough information to calculate this. Mass number (\(A\)): We do not have enough information to calculate this. Finally, for the fifth atom with 37 protons: Symbol: The element with 37 protons is Rubidium (Rb) Number of neutrons (\(n\)): Using the relationship \(A = p + n\), we get \(n = A - p = 85 - 37 = 48\). Number of electrons (\(e\)): Since it is a neutral atom, e = p = 37. Mass number (\(A\)): The given mass number is 85. Now we can fill in the table with the derived information.

Step 3: Fill in the table with the derived information

After deriving the information, we can fill in the table: $$ \begin{array}{l|c|c|c|c|c} \hline \text { Symbol } & { }^{159} \mathrm{Tb} & {}^{\mathrm{?}}\mathrm{Cu} & & {}^{\mathrm{?}}\mathrm{Se} & { }^{85} \mathrm{Rb} \\ \text { Protons } & 65 & 29 & & 34 & 37 \\ \text { Neutrons } & 94 & & 53 & & 48 \\ \text { Electrons } & 65 & 29 & 42 & 34 & 37 \\ \text { Mass no. } & 159 & & & & 85 \\ \hline \end{array} $$ As seen in the table above, we have filled all the possible gaps with the given information.