Question

four molecule models are shown
model 1 model 2 model 3 model 4
water is composed of two hydrogen atoms
and one oxygen atom. which model most
likely contains only water?
☐ model 3
☐ model 4
☐ model 1
☐ model 2

Explanation:

Step1: Recall water's molecular structure

Water (\(H_2O\)) has 2 H atoms and 1 O atom per molecule. So each water molecule should have a ratio of 2 small (H) and 1 large (O) atom, or a group with 2 of one color and 1 of another.

Step2: Analyze each model

• Model 1: All molecules are the same blue, single - type, no ratio of 2:1. Not water.
• Model 2: Molecules have 2 small (green) and 1 large (blue) atoms (or vice - versa, but ratio 2:1). Matches \(H_2O\) ratio.
• Model 3: Molecules have 2 orange and 1 blue? Wait, no, the ratio here looks like 2:1? Wait, no, wait the description: water is 2 H and 1 O. Model 2: let's see the colors. Model 2 has molecules with 2 green (small) and 1 blue (large) or 2 blue and 1 green? Wait, no, the key is the ratio of 2:1 for two different atom types. Model 2: each molecule has 2 of one color and 1 of another, which is the ratio for \(H_2O\) (2 H, 1 O). Model 3: molecules have 2 orange and 1 blue? Wait, no, maybe I mis - saw. Wait, the problem says water is 2 H and 1 O. So the molecule should have 2 of one atom (H) and 1 of another (O). So Model 2: each molecule has 2 small (H) and 1 large (O) atoms (or 2 large and 1 small, but the ratio is 2:1). So Model 2's molecules have a 2:1 ratio of two different atom types, which matches \(H_2O\). Model 1: single - type, Model 3: maybe different ratio, Model 4: two different molecule types (orange and green). So Model 2 is the one with only water molecules (each with 2 H and 1 O atoms, represented by two of one color and one of another).

Answer:

Model 2