Which feature is used to classify galaxies? age, color ,shape, size wich one need asap

The correct answer is Shape.

Explanation:

Galaxies are defined as the system of million or billions of stars along with gas and dust held together by gravitational attraction.

These are classified as 3 types on the basis of its shape:

1. Spiral galaxy: It is defined as the galaxy in which stars and gas clouds are located mainly in one or more spiral arms. Example: Milky Way

2. Elliptical galaxy: It is defined as the galaxy which has ellipsoidal shape and a smooth, featureless image. Example: M-110.

3. Irregular galaxy: It is defined as the galaxy that does not have any distinct regular shape. Example: Irr-I galaxy.

Hence, the correct answer is Shape.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i