To determine which processes are endothermic, let's analyze each process step-by-step:
1. Boiling water to steam:
- Boiling involves turning liquid water into steam, which requires energy to overcome the intermolecular forces holding the water molecules together. Hence, energy is absorbed from the surroundings.
- This process is endothermic.
2. Condensation of steam to water:
- Condensation is the process of steam (gas) becoming liquid water, which happens when the steam loses energy and the molecules come closer together.
- This process releases energy into the surroundings.
- This process is exothermic.
3. [tex]\(Na \rightarrow Na ^{+}+ e ^{-}\)[/tex]:
- This represents the ionization of sodium, where a neutral sodium atom loses an electron to form a positively charged sodium ion. Energy is required to remove an electron from an atom.
- This process is endothermic.
4. Running for 30 minutes:
- Running is a physical activity and not a chemical process. Hence, it is not characterized as endothermic or exothermic in the context of chemical reactions.
- This process is not applicable to be considered endothermic or exothermic.
5. [tex]\(Cl _2 \rightarrow 2 Cl\)[/tex]:
- This equation represents the dissociation of a chlorine molecule into two chlorine atoms. Breaking the bond between the two chlorine atoms requires energy.
- This process is endothermic.
Thus, the endothermic processes from the given options are:
- Boiling water to steam
- [tex]\(Na \rightarrow Na ^{+}+ e ^{-}\)[/tex]
- [tex]\(Cl _2 \rightarrow 2 Cl\)[/tex]
So, the correct answers are:
1. Boiling water to steam
3. [tex]\(Na \rightarrow Na ^{+}+ e ^{-}\)[/tex]
5. [tex]\(Cl _2 \rightarrow 2 Cl\)[/tex]
