test 5

Question 1

The closest distance you can get from a black hole with some possibility of escaping is called the event

horizon.

True

False

Question 2

The product of helium fusion is

lead

argon

carbon

zinc

uranium

Question 3

It's possible for both hydrogen and helium reactions to occur simultaneously in the same star.

True

False

Question 4

Cygnus X-1 is

a brand of motor oil

non of these

a black hole

a galaxy

Question 5

Spheroidal-population stars tend to be located in our galaxy's halo.

True

False

Question 6

A neutron star is about the size of a

planet

none of these

football field

small city

house

Question 7

Our galaxy has 100 thousand stars at the most.

True

False

Question 8

Stars tend to form in a spiral galaxy's arms.

True

False

Question 9

The cutoff point between high- and low-mass stars is

half the mass of the Sun

three times the mass of the Sun

none of these

all of these

twice the mass of the Sun

Question 10

Stars in the process of forming are called

protostars

prestars

quasars

neostars

none of these

Question 11

Nuclear fusion reactions can occur at temperatures below 10 thousand K.

True

False

Question 12

No star spends more than 70 percent of its life on the main-sequence.

True

False

Question 13

Many elements heavier than hydrogen and helium came into existence in the early history of the

Universe.

True

False

Question 14

Our galaxy is unusual in that it lacks a supermassive black hole at its center.

True

False

Question 15

Near the end of a small star's life nuclear reactions involving many different kinds of atoms occur.

True

False

Question 16

The most common stars in the Universe have very high masses.

True

False

Question 17

About how long did it take the Sun to form?

10 thousand years

1 billion years

30 million years

one-and-a-half years

none of these

Question 18

The end stage of a star like the Sun will be a

white dwarf

all of these

black hole

neutron star

none of these

Question 19

Degeneracy pressure is a consequence of quantum mechanics.

True

False

Question 20

There are occasions in close binary systems when stars can exchange mass.

True

False

Question 21

Most of our galaxy's matter is currently believed to be located in its halo.

True

False

Question 22

A planetary nebula is a planet in the process of forming.

True

False

Question 23

Helium capture reactions result in a relatively large amount of odd-numbered elements.

True

False

Question 24

Heavy elements---those more massive than hydrogen or helium---make up about 50% of the atoms in

the Universe.

True

False

Question 25

A star that tried to form but failed is called a

blue dwarf

green dwarf

red dwarf

brown dwarf

white dwarf

Question 26

No star in the Universe has more than 50 times the mass of the Sun.

True

False

Question 27

The Sun takes about how long to orbit the center of the galaxy.

5 years

1 million years

10 billion years

1 billion years

230 million years

Question 28

The crab nebular supernova was first observed

just under a thousand years ago

about a million years ago

last week

in 1968

about three thousand years ago

Question 29

Stars become giant early in their lives.

True

False

Question 30

You can tell the difference between a nova and a supernova by measuring how bright they are.

True

False

Question 31

What do stars form from?

polyunsaturated fats

grains of iron

all of these

clouds of gas and dust

none of these

Question 32

The heaviest element produced in a high-mass star before it turns into a supernova is

plutonium

xenon

radium

iron

iodine

Question 33

About what percentage of stars are members of binary systems?

50

25

100

75

0