Magnesium and calcium have similar chemical properties because their atoms in the ground state have 1.
equal numbers of protons and electrons
2.
equal numbers of protons and neutrons
3
two electrons in the first shell
4.
two electrons in the outermost shell

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?