Answer:
Dana filtered the sample and larger granules of the sample were left behind.
Explanation:
If a substance is pure, it will have a uniform composition throughout. It will not separate into particles of various sizes.
One of the characteristics of pure substances is that they are homogeneous. A mixture is definitely made up of particles of various sizes.
Since the particles was filtered and larger granules were left behind, the sample has been separated by a physical method (filtration). Only a mixture can be separated by physical methods. It is not a pure substance.
Seven
Elements do not contain more than 7 electron shells.
Answer:
Aluminium.
Explanation:
The above electronic configuration can be written in a simplified form as shown below:
1s² 2s²2p⁶ 3s²3p¹
Next, we shall determine the number of electrons in the atom of the element as follow:
Number electron = 2 + 2 + 6 + 2 + 1
Number of electron = 13
Next, we shall determine the number of protons.
Since the element is in its neutral state,
The number of electrons and protons are equal i.e
Proton = Electron
Number of electron = 13
Proton = Electron = 13
Proton = 13
Next, we shall determine the atomic number of the element.
The atomic number of an element is simply the number of protons in the atom of the element i.e
Atomic number = proton number
Proton = 13
Atomic number = 13
Comparing the atomic number of the element with those in the periodic table, the element with the above electronic configuration is aluminium since no two elements have the same atomic number.
Answer:
Explanation:
Catalyst is I2 . Because I2 is reacted with starting material in step 1 and generated in second step
Rate limiting step is step 1. Because in rate equation CH3CHO and I2 is mentioned. Hence the overall rate of reaction is depending CH3CHO and I2. Rate limiting step is step 1
