In the early periodic tables some elements were placed in the wrong groups Mendeleev overcame some of these problems in his periodic table
Give two ways Mendeleev did this.

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

hope it

dynamic equilibrium is the answer.

the answer is 0.42 is that is an option. this question provides no info