Drag and drop the words into the correct locations. Answers may be used once, more than once, or not at all. (1 point)
Put responses in the correct input to answer the question. Select a response, navigate to the desired input and insert the response. Responses can be selected and inserted using the space bar, enter key, left mouse button or touchpad. Responses can also be moved by dragging with a mouse.
Galaxies can be grouped by the age of the stars they tend to contain, with Response area galaxies having the youngest stars and Response area galaxies having the oldest stars.
1. Spiral
2. Elliptical
3. Irregular
Which proportion of the universe's galaxies can be seen from Earth?(1 point)
Responses
approximately 10 percent
approximately 10 percent
far less than 1 percent
far less than 1 percent
nearly half
nearly half
approximately 25 percent
far less than 1 percent
Which event triggers the start of black hole formation?(1 point)
Responses
A supernova blows a massive star apart.
A supernova blows a massive star apart.
Radiation emitted by a massive star increases.
Radiation emitted by a massive star increases.
The gravitational forces acting on a massive star decline rapidly.
The gravitational forces acting on a massive star decline rapidly.
A massive star depletes its stores of hydrogen and helium.
A massive star depletes its stores of hydrogen and helium.
A supernova blows a massive star apart.
Select the correct answers from the list.(1 point)
One model of galaxy formation occurs when sections of gas clouds collapse into small pieces and then merge into larger pieces due to gravity. The Milky Way is an example of the
model or the
model.
One model of galaxy formation occurs when sections of gas clouds collapse into small pieces and then merge into larger pieces due to gravity. The Milky Way is an example of the hierarchical model or the merging model.
Why are most stars not destroyed in a galaxy collision?(1 point)
Responses
Galaxies don't have stars.
Galaxies don't have stars.
Galaxies are mostly empty space.
Galaxies are mostly empty space.
Gravity keeps them away from each other.
Gravity keeps them away from each other.
Galaxies move too slowly for that type of damage.
Gravity keeps them away from each other.
What do supernova remnant and planetary nebulae have in common? Select the three correct answers.(2 points)
Responses
They are composed of matter from dying stars.
They are composed of matter from dying stars.
They are composed only of hydrogen and helium.
They are composed only of hydrogen and helium.
They are diffuse.
They are diffuse.
They contribute matter to interstellar space.
They contribute matter to interstellar space.
They have planets circling them.
They have planets circling them.
They emit non-visible radiation.
They emit non-visible radiation.