A felsic magma has high content of silicate minerals. Quartz and feldspar are silicate minerals with a high content of silica in them. Magma with such a rich composition of quartz and feldspar is known as a felsic magma.
Explanation: All gases are diatomic i.e they are covalently bonded to another atom of the same element in order to attain stability. O atom is usually unstable because of it's incompletely filled outermost shell.