The correct option is C.
The pitch of a string refers to the quality of sound that is produced by the string when it vibrates. There are three basic factors that affect the quality of pitch of a string, these are: the tension, the thickness of the string and the length of the string. The higher the thickness of the string, the lower the pitch of the string, thus, increasing the thickness of the string will lower the pitch.
An electron is a negatively charged subatomic particle present in the space outside the nucleus of an atom. The loss of electron from an atom results in the formation of cation whereas gaining of electron by an atom results in the formation of anion. The cation possesses positive charge due to loss of electron and anion possesses negative charge due to gain of electron.
The neutral atom has no charge on it.
For given atomic symbols:
The atomic number of hydrogen is 1 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in
is 1.
The atomic number of helium is 2 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in
is 2.
The atomic number of hydrogen is 1 and the given symbol has a negative charge that represents a gain of electron. So, the number of electrons in
is 2.
The atomic number of helium is 2 and the given symbol has two positive charge that represents loss of two electrons. So, the number of electrons in
is 0.
Hence,
has no electrons.