Answer:
All of the above are true
Explanation:
a) The emission spectrum of a particular element is always the same and can be used to identify the element: It's true since the emission spectrum for each element is unique. It has the same bright lines at the same wavelength. This feature is used to identify elements. For example, the study of the emission spectra of light arriving from stars allow us to identify the elements presents in the star because the light contains the emission spectra of those elements.
b)The uncertainty principle states that we can never know both the exact location and speed of an electron: It is true since the velocity of an electron is related to its wave nature, while its position is related to its particle nature and we cannot simultaneously measure electron's position and velocity with precision.
c) An orbital is the volume in which we are most likely to find an electron: An orbital is a probability distribution map that is used to decribe the likely position of an electron in an atom.
A. <span>the layer of rock and mineral fragments that covers nearly all of Earth's land surface</span>
Answer: The molar enthalpy change is 73.04 kJ/mol
Explanation:
moles of HCl=
As NaOH is in excess 0.0415 moles of HCl reacts with 0.0415 moles of NaOH.
volume of water = 100.0 ml + 50.0 ml = 150.0 ml
density of water = 1.0 g/ml
mass of water =
q = heat released
m = mass = 150.0 g
c = specific heat =
= change in temperature =
Thus 0.0415 mol of HCl produces heat = 3031.3 J
1 mol of HCL produces heat =
Thus molar enthalpy change is 73.04 kJ/mol
Answer is only B.
<span>it becomes more stable</span>
Must be Selenium (Se). It is two space away from Kr, which means that it needs two extra electron to be like a noble gas, Kr.