Answer: gradual increase in temperature of ice from −15°C to 0°C, holding at 0°C as ice melts to water
Explanation: The heat used to convert solid to liquid is gained by molecules to gain kinetic energy and thus the molecules start moving faster and the temperature increases.
But as the melting point is approached i.e. , the temperature remains constant as now the heat given is used to break the inter molecular forces and thus is not reflected in terms of temperature increase. This hidden heat is called as latent heat.
The temperature remains constant till the phase change is complete.
I’m pretty sure it will be the answer choice B
Answer:
4Al2O3 + 9Fe --> 3Fe3O4 + 8Al
Explanation:
Al:8 Al:8
O:12 O:12
Fe:9 Fe:9
just make sure that both sides have the same ammount. I started with Iron, balenced it to 3, then made sure i had 12 oxygen on both sides, being that i had 3 iron on the left and 9 on the right so i went back and fixed that. I then saw that i had 8 Al on the left and 1 on the right so i balenced that
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.