The elements whose electron configurations end with f electrons are in the Lanthanide and Actinide series: those long series at the bottom of the Periodic Table (see image).
The atoms are adding electrons into f orbitals, but the f electrons are not always the last electrons in the electron configuration.
For example, the electron configuration of Eu is [Xe]6s²4f⁷, but that of Gd
is [Xe] 6s²4f⁷5d.
I have blocked off in <em>red</em> all the <em>exceptions</em> like Gd.
Answer: True
Explanation:
Weak electrolytes are those solutions which do not undergo complete dissociation when dissolved in water. The dissociation of weak electrolytes is given by an equilibrium.
Example: 
Strong electrolytes are those solutions which undergo complete dissociation when dissolved in water. The dissociation of strong electrolytes is given by a right arrow.
Example: 
Thus the degree to which various compounds will dissociate in solution varies greatly is true.
Hydrogen peroxide mixed with vinegar makes peracetic acid, which is a toxic gas that irritates the skin and respiratory system
Answer: Scientist shoot a whole bunch of neutrons at uranium-235 atoms. When one neutron hits the nucleus the uranium becomes U-236. When it becomes 236, the uranium atoms wants to spilt apart. After it splits it gives off three neutrons and a lot of energy.
Explanation:
D water expands when it freezes