If you drop a 25-gram piece of metal that has a temperature of 100° celsius into 1000 grams of water at 20° celsius, what best describes what would occur? 1. the temperature lost by the metal will equal the temperature gained by the water 2. the heat lost by the metal will equal the heat gained by the water 3. the final temperature will be 60 degrees celsius 4. the final temperature will be more than 60 degrees celsius

Answer is: 2. the heat lost by the metal will equal the heat gained by the water.

1) the temperature lost by the metal will equal the temperature gained by the water is not correct, because temperature is the intensity of heat present in a substance and a thermometer is a device that measures temperature or a temperature gradient.

3) the final temperature will be 60 degrees celsius  is not correct, because amount of water is greater than amount of metal, so the the final temperature will be less than 60 degrees celsius.

4) same as 3).

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.