1.the order in which we think the first stars formed. Put the steps in order. a A dense, hot gas ball forms at the center of a nebula, called a protostar. b The star burns hot, quickly exhausting its fuel and exploding in a supernova. c Nebulae condense into swirling disks due to the particle-to-particle attraction of gravity. d Hydrogen and helium form swirling clouds called nebulae. e Heat and pressure from the increasing density of gas causes nuclear fusion to take place. 2.Which of the following correctly summarizes how new elements are created by stellar nucleosynthesis/supernova nucleosynthesis? a Stars first combined hydrogen to form helium. Over time, those stars continually combined heavier and heavier elements until they became so dense that the stars collapsed, spreading the elements through the universe. b Stars blow atoms they fuse out into space through the solar wind. When a star blows up, it makes heavy atoms. c When stars collide, the heat and pressure of the collision forms new elements. d When a star burns, it fuses elements together to make heavier elements. When it burns out and explodes into a supernova, elements fuse together to make heavy elements. As this process repeated through time, heavier and heavier elements were created. 3.Which of the following correctly describes how dust and gas formed planets? a Gravity slowly pulled particles together into larger and larger masses within rings of the protoplanetary disk. The larger the masses became, the greater the gravitational pull. b The heat of the protoplanetary disk caused materials to melt together into clumps. Collisions of these masses grew into planets. c Dust and ice collided violently, smashing material together into planetesimals. d The solar wind forced material to gather into rings, and then material collided as it orbited the sun, combining into huge collections of dust and gas and eventually melting into planets. a A dense, hot gas ball forms at the center of a nebula, called a protostar. b The star burns hot, quickly exhausting its fuel and exploding in a supernova. c Nebulae condense into swirling disks due to the particle-to-particle attraction of gravity. d Hydrogen and helium form swirling clouds called nebulae. e Heat and pressure from the increasing density of gas causes nuclear fusion to take place..

1. 1.the order in which we think the first stars formed. Put the steps in order.
a
A dense, hot gas ball forms at the center of a nebula, called a protostar.
b
The star burns hot, quickly exhausting its fuel and exploding in a supernova.
c
Nebulae condense into swirling disks due to the particle-to-particle attraction of gravity.
d
Hydrogen and helium form swirling clouds called nebulae.
e
Heat and pressure from the increasing density of gas causes nuclear fusion to take place.
2.Which of the following correctly summarizes how new elements are created by stellar
nucleosynthesis/supernova nucleosynthesis?
a
Stars first combined hydrogen to form helium. Over time, those stars continually combined
heavier and heavier elements until they became so dense that the stars collapsed, spreading the
elements through the universe.
b
Stars blow atoms they fuse out into space through the solar wind. When a star blows up, it makes
heavy atoms.
c
When stars collide, the heat and pressure of the collision forms new elements.
d
When a star burns, it fuses elements together to make heavier elements. When it burns out and
explodes into a supernova, elements fuse together to make heavy elements. As this process
repeated through time, heavier and heavier elements were created.

2. 3.Which of the following correctly describes how dust and gas formed planets?
a
Gravity slowly pulled particles together into larger and larger masses within rings of the
protoplanetary disk. The larger the masses became, the greater the gravitational pull.
b
The heat of the protoplanetary disk caused materials to melt together into clumps. Collisions of
these masses grew into planets.
c
Dust and ice collided violently, smashing material together into planetesimals.
d
The solar wind forced material to gather into rings, and then material collided as it orbited the
sun, combining into huge collections of dust and gas and eventually melting into planets.
a A dense, hot gas ball forms at the center of a nebula, called a protostar.
b The star burns hot, quickly exhausting its fuel and exploding in a supernova.
c Nebulae condense into swirling disks due to the particle-to-particle attraction of gravity.
d Hydrogen and helium form swirling clouds called nebulae.
e Heat and pressure from the increasing density of gas causes nuclear fusion to take place.