Yes, the water has turned into ice. It was a liquid but it is now a solid. You can change it back again by melting it.
metal cup because it has insulation
A paper cup typically does not keep water hotter than a plastic cup. Paper is a poor insulator compared to plastic, so heat is more likely to escape from a paper cup, leading to faster cooling of the water inside.
Froze is the past tense of freeze. An example sentence would be: She left her cup in the snow and it froze.
Yes it will .
Tap water out of a paper cup uses the fewest resources from the environment tap water out of a plastic cup.
That depends on how hot the water is in the cup. Use the thermometer to measure it and see.
A plastic cup may help insulate cold water for a short period of time, but it is not as effective as an insulated container. The thickness of the plastic and the ambient temperature will also affect how long the water stays cold.
The cup may be damaged.
Glass would be healthier
You're talking about holding the temperature of the water, right? As far as containing the liquid, they're about equal...but a styrofoam or double-wall plastic cup would hold temp better than a glass cup which would work better than a single-wall plastic cup.
A plastic cup is a good conductor of heat, meaning it allows heat to transfer quickly out of the cup and into the water, helping it cool down faster. The plastic material also has less thermal mass than glass or ceramic, so it cools down faster itself, helping to cool the water more efficiently.
The cold lemonade cool the temperature of the plastic cup including the outer side of it. Thereby lowering the amount of water the air can contain, resulting in water condensating - attaching to the cup.