Answer:
Isotopes are basically atoms of an element that have an unequal number of neutrons and protons. Of course the proton number remains the same, but the neutron number either decreases or increases, which leads to an overall change in mass. However, no chemical properties of the atom/element are changed as the electrons are the same number and do not react. In regards to Helium 4, the original number of neutrons in Helium is 2, and protons 2 as well. We see an equal number of neutrons and protons, hence an unchanged mass, and the element is <em>not</em> an isotope.
Answer:
A chemical reaction is the change in chemical form rather than physical due to an outside force. This can come from something as simple as a change in temerature to as large as a specific element or compound.
Answer:
9.6 %
Explanation:
<u>Step 1: How to define percent error ? </u>
⇒ % error is the difference between a measured value and the known or accepted value
⇒Percent error is calculated using the following formula:
⇒%error = | Experimental value-theoretical value/theoretical value | x100%
⇔ this can be written as well as : error = (| Experimental value/ theoretical value | - | Theoretical value / Theoretical value | ) x100%
<u>Step 2: Calculate % error</u>
In this case, this means :
%error = ( |(4.45 cm - 4.06cm ) / 4.06cm | ) x100%
%error = 0.096 x100%
%error =9.6 %
0.00044
Zeros to the right of the decimal place are not significant UNLESS they are found in between or after a non-zero number, therefore, we take the 3200 away because those ARE significant so then after you round your answer (if needed) you're left with only two numbers that are significant.
Answer:
It is heterogeneous as it is made up of visibly different substances or phases.
