Ms. Pitt set up a classroom demonstration to show what happens when a sample of zinc metal is added to a flask containing hydrochloric acid (HCl). The diagram shows what the students in the classroom observed during the demonstration. The students made two other observations:
The flask felt warmer after adding the sample.
The sample became smaller over time.
a. Explain why the change to the balloon is evidence of a chemical reaction.
b. Explain why the flask feeling warmer after the sample was added is evidence of a chemical reaction.
The students learn that zinc metal does not dissolve in HCl.
c. Explain why the sample becoming smaller over time in HCl is evidence of a chemical reaction.

specific gravity is the density of a substance divided by the density of water. since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density

so "c" is the answer

plz give brainliest

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

question: ray weighs 100 kilograms, his wrestling partner, bobby, weighs 50 kilograms. if ray moves at 4 m s , how fast will bobby have to run at him to apply an equal amount of kinetic energy?

answer: 8 m/s he needs to run twice as fast to keep up so he has some work to do

explanation:   if the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

question answered by

(jacemorris04)