SEP Develop Models Each helium atom has two protons. Sketch models of helium-3 and helium-4, which have approximate masses of 3 amu
and 4 amu, respectively. Label and differentiate protons, neutrons, and
electrons in your models?

Protons and neutrons are located in the nucleus of the atom while the electrons move in the trajectory of the shell

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.  

So Isotopes are elements that have the same Atomic Number (Proton)  

Isotopes of Helium : helium-3 and helium-4

protons = 2

electrons=protons=2

neutron=mass number-atomic number=3-2=1

protons = 2

electrons=protons=2

neutron=mass number-atomic number=3-2=1

protons = 2

electrons=protons=2

neutron=mass number-atomic number=4-2=2

Protons and neutron in the nucleus, electrons in the shell

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the formula for the conversion of temperature from degree celsius to kelvin is:

the sample of water at is converted to kelvin temperature by using the above formula as:

on comparing the two samples of water at or we can say that at and at respectively. the difference between the temperatures of two samples of water is:

hence, one can say that the sample of water at is greater than the sample of water at by .