In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products?(1 point)

To determine which equation has the same number of atoms in the reactants and products, we need to look at the conservation of mass, which states that atoms in a chemical reaction must be balanced.

1. **Li2CO3 → LiO + CO2**
- Reactants: 2 Li + 1 C + 3 O = 6 atoms
- Products: 1 Li + 1 O + 1 C + 2 O = 4 atoms
- Not balanced.

2. **CO2 + H2O → CH2OH + O2**
- Reactants: 1 C + 2 O + 2 H = 5 atoms
- Products: 1 C + 1 H + 2 O + 1 O = 5 atoms
- Balanced.

3. **Zn + 2HCl → H2 + ZnCl2**
- Reactants: 1 Zn + 2 H + 2 Cl = 5 atoms
- Products: 1 Zn + 2 Cl + 2 H = 5 atoms
- Balanced.

4. **CH4 + O2 → CO2 + 2H2O**
- Reactants: 1 C + 4 H + 2 O = 7 atoms
- Products: 1 C + 2 O + 4 H = 7 atoms
- Balanced.

From the analysis, the following equations are balanced (the number of atoms in reactants equals the number of atoms in products):

- **CO2 + H2O → CH2OH + O2**
- **Zn + 2HCl → H2 + ZnCl2**
- **CH4 + O2 → CO2 + 2H2O**

However, focusing on your original query for a specific choice that matches “the number of atoms in the reactants the same as the number of atoms in the products,” the two selected options with reactions copy can be either **Zn + 2HCl → H2 + ZnCl2** **or** **CH4 + O2 → CO2 + 2H2O**.

If asked for just one of them, you can select either based on additional context or preferences from your assignment, or if there is no preference, **Zn + 2HCl → H2 + ZnCl2** is often a straightforward equation used in examples of balanced reactions.