Answer:
II) Objects made of silver become tarnished.
Explanation:
Physical properties are the properties which can be observed without changing identity of substance.
Chemical properties are the properties which describe how the substance changes into the different substance completely.
Boiling is an example of physical change in state of the substance. Color is also an example of physical property like boiling point and hence these are constants. The reason of the color is that the chromium ions shows certain colors as the electrons are excited due to absorption of the light. The tarnishing of the silver is an example of the chemical change which occurs due to the reaction of the silver with oxygen. This is also known as corrosion.
A substance that contains two or more kinds of atoms is a molecule.
B - CCL4
This is because it doesn't say Dicarbon or any of that sort, so Carbon is alone. This immediately eiminates the option of C.
A is incorrect as it has Chlorine first rather than Carbon, so that's also incorrect.
D is incorrect as 7 is hepta rather than tetra.
The list is as so;
Mono - 1; Di - 2; Tri - 3; Tetra - 4; Penta - 5; Hexa - 6; Hepta - 7; Octa - 8; Nona - 9; Deca - 10.
Hope this helps!
<u>Answer:</u> The true statements are
for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings,
is negative.
<u>Explanation:</u>
There are 2 types of chemical reactions categorized into heat change:
- <u>Endothermic reactions:</u> These reactions are defined as the reactions in which energy is absorbed by the system from the surroundings. The
for these reactions is always positive. For Example: Changing of water into water vapor. - <u>Exothermic reactions:</u> These reactions are defined as the reactions in which energy is released by the system to the surroundings. The
for these reactions is always negative. For Example: Combustion reactions.
Combustion reactions are defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water. Heat is released during these reactions. Thus, it is considered as exothermic reactions.
Hence, the true statements are
for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings,
is negative.
Answer:
Number of proton emmitted by laser=
Explanation:
Energy is the ability to cause change; power is directly proportional to energy and its the rate energy is utilized.
Power=energy/time.
First we need to calculate the total energy used which is equal to the total power utilized.
E(total)= P( total) = 1.4W × 0.070 s =
CHECK THE ATTACHMENT FOR THE REMAINING DETAILED CALCULATION