The Spectral Classification of Stars Started with the Amount of Hydrogen

question 43

True/False

The spectral classification of stars started with the amount of hydrogen present in their spectra, but a better method now uses the amount of oxygen in the star's spectra.

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Definitions:

Fixed

A term that describes something that is securely attached, unchanging, or incapable of being altered.

Fontanels

Soft spots on an infant's skull that allows for growth of the head during the first year.

Tonic Neck Reflex

An infant reflex where turning the head to one side causes the arm on that side to stretch out and the opposite arm to bend at the elbow.

Head Circumference

A measurement around the largest part of the skull, used in medical contexts to assess brain growth and development, especially in infants and young children.