160 140
120
100
Temperature (°C)
80
60
40
20
0
0
2 4 6 8
10 12 14 16 18 20 22 24 26
Time (min)
.
At what temp will this substance freeze? 70 CV
At what temp will this substance condense? 70 C
How long will it take to release the heat of vaporization? 3 min
What is the melting point? 70 C
In what physical state did this substance end? Gas
All cooling processes, including phase changes, are Exothermic
At 90 C, what phase of matter is this substance? Liquid

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium

The table lists the lattice energies of some compounds.compoundlattice energy (kj/mol)lif            –1,036licl            –853naf            –923kf            –821nacl            –786which statement about crystal lattice energy is  best  supported by the information in the table? the lattice energy increases as cations get smaller, as shown by lif and kf.the lattice energy increases as the cations get larger, as shown by lif and licl.the lattice energy decreases as cations get smaller, as shown by nacl and naf.the lattice energy decreases as the cations get smaller, as shown by naf and kf.