Answer:
if you are working with hazardous materials.
Explanation:
A properly operating and correctly used fume hood can reduce or eliminate exposure to volatile liquids, dusts, and mists. It is advisable to use a laboratory hood when working with all hazardous substances.
Chemical reactions that release energy will not occur without a source of energy. So the answer is release.
Answer : The correct option is, Mass
Explanation :
As we know that there are 3 states of matter :
Solid state : It is a state in which the particles are closely packed and does not have any space between them. This state have a definite shape and volume.
Liquid state : It is a state in which the particles are present in random and irregular pattern. The particles are closely arranged but they can move from one place to another. This state have a definite volume but does not have a fixed shape.
Gaseous state : It is a state in which the particles are loosely arranged and have a lot of space between them. This state have indefinite volume as well as shape.
If we are taking 100 grams of ice then after melting its mass remains same but its shape, volume and temperature will be changed and after evaporation its mass remains same but its shape, volume and temperature will be changed.
Hence, the mass will stay constant, no matter if the substance is in the solid, liquid, or gas state.
<span>If you look up the density of Acetone (Propanone in IUPAC names) you will find it is 0.7925g/cm3. This is the same as 0.7925g/ml.
You can calculate mass using the equation:- mass = density x volume
In your example mass = 0.7925 x 28.40 = 22.51g</span><span>
I think That's right. Hope this helps!!! Good luck!</span>
Option C: the electrons are embedded in a positive sphere.
As we know that was a wrong model and nowadays the electrons are considered to be around the nucleus, in regions called orbitals.
