In the case of the calcium ion, we have a calcium element with a positive charge of 2. Positively charged atoms are called cations. This simply means that the element calcium needs two more electrons to equal the number of protons that it has; this balances the charge, or makes it zero
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Vary in the number of neutrons but Sama in the number if protons are called isotopes
So: both parents' genotypes (concerning baldness gene) are the same: Bb. Possible genotypes of an offspring: BB, Bb, Bb, bb . bb means non-bald girl or boy. Bb means bald boy or non-bald girl. BB means bald boy or girl. there is 25% chance of conceiving a child with a genotype BB. But there is also 50% chance of conceiving a girl. So the answer is: 25% x 50% = 12,5%