What do supernova remnant and planetary nebulae have in common? Select the three correct answers.(2 points)
Responses
They are composed only of hydrogen and helium.
They are composed only of hydrogen and helium.
They emit non-visible radiation.
They emit non-visible radiation.
They are composed of matter from dying stars.
They are composed of matter from dying stars.
They have planets circling them.
They have planets circling them.
They contribute matter to interstellar space.
They contribute matter to interstellar space.
They are diffuse.
They are diffuse.
They emit non-visible radiation.
They are composed of matter from dying stars.
They contribute matter to interstellar space.
The three correct answers are:
1. They are composed of matter from dying stars.
2. They contribute matter to interstellar space.
3. They emit non-visible radiation.
The correct answers are:
1. They are composed of matter from dying stars.
2. They contribute matter to interstellar space.
3. They emit non-visible radiation.
To determine the correct answers, we need to understand the characteristics and definitions of supernova remnants and planetary nebulae.
1. Supernova remnants: These are formed when a massive star undergoes a supernova explosion, releasing a tremendous amount of energy and ejecting matter into space. Supernova remnants are composed of the remnants of the original star, including heavier elements formed through nucleosynthesis. Therefore, they are composed of matter from dying stars.
2. Planetary nebulae: These are formed during the late stages of low-to-medium mass stars' evolution. As a star exhausts its nuclear fuel, it undergoes a series of expansions and contractions, shedding its outer layers into space. These ejected layers form a glowing shell of gas and dust called a planetary nebula. Like supernova remnants, planetary nebulae also contribute matter to interstellar space.
3. Both supernova remnants and planetary nebulae emit non-visible radiation. When a massive star undergoes a supernova explosion, it releases a burst of energy across the electromagnetic spectrum, including visible and non-visible radiation such as X-rays and gamma rays. Planetary nebulae also emit a range of radiation, including ultraviolet and infrared light.
Therefore, the common characteristics of supernova remnants and planetary nebulae are that they are composed of matter from dying stars, contribute matter to interstellar space, and emit non-visible radiation.
Which proportion of the universe's galaxies can be seen from Earth?(1 point)
Responses
approximately 10 percent
approximately 10 percent
approximately 25 percent
approximately 25 percent
far less than 1 percent
far less than 1 percent
nearly half
far less than 1 percent
Which was used to create the first image of a black hole?(1 point)
Responses
x-rays from inside the black hole
x-rays from inside the black hole
ultraviolet light from objects in the black hole
ultraviolet light from objects in the black hole
radio waves from matter at the edge of the black hole
radio waves from matter at the edge of the black hole
visible light from the black hole
radio waves from matter at the edge of the black hole
Which event triggers the start of black hole formation?(1 point)
Responses
Radiation emitted by a massive star increases.
Radiation emitted by a massive star increases.
A supernova blows a massive star apart.
A supernova blows a massive star apart.
A massive star depletes its stores of hydrogen and helium.
A massive star depletes its stores of hydrogen and helium.
The gravitational forces acting on a massive star decline rapidly.
A supernova blows a massive star apart.
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 (elliptical/spiral/irregular) area galaxies having the youngest stars and (elliptical/spiral/irregular) area galaxies having the oldest stars.
Galaxies can be grouped by the age of the stars they tend to contain, with elliptical galaxies having the oldest stars and spiral galaxies having the youngest stars.
The universe's galaxies have evolved since what point in time?(1 point)
Responses
23.4 billion years ago, when the universe first formed
23.4 billion years ago, when the universe first formed
13.8 billion years ago, right after the universe first formed
13.8 billion years ago, right after the universe first formed
800 million years ago, when gas concentrations were optimal for galaxy formation
800 million years ago, when gas concentrations were optimal for galaxy formation
approximately 50 million years ago, after initial clumps of material were formed
13.8 billion years ago, right after the universe first formed
Why are most stars not destroyed in a galaxy collision?(1 point)
Responses
Galaxies move too slowly for that type of damage.
Galaxies move too slowly for that type of damage.
Gravity keeps them away from each other.
Gravity keeps them away from each other.
Galaxies are mostly empty space.
Galaxies are mostly empty space.
Galaxies don't have stars.
Galaxies move too slowly for that type of damage.
Which of the following is an accurate description of cosmic microwave background (CMB) radiation? (1 point)
Responses
CMB increases across the universe.
CMB increases across the universe.
CMB is remnant radiation from the Big Bang.
CMB is remnant radiation from the Big Bang.
CMB is constantly generated by stars.
CMB is constantly generated by stars.
CMB produces differing temperatures across the universe.
CMB is remnant radiation from the Big Bang.
2 answers for that one
Apologies for the confusion. The two accurate descriptions of cosmic microwave background (CMB) radiation are as follows:
1. CMB is remnant radiation from the Big Bang.
2. CMB produces differing temperatures across the universe.
Which of these describes a nebula?(1 point)
Responses
cloud of gas and dust
cloud of gas and dust
cloud of gravity and pressure
cloud of gravity and pressure
star close in size to the sun
star close in size to the sun
star much larger than the sun
A nebula is a cloud of gas and dust.
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 (inside-out/outside-in) model or the (top-down/bottom-up) model.