If you put a lump of solid carbon dioxide (dry ice) in a paper cup or
on a paper plate on the kitchen counter, it gets smaller and smaller
and finally it just disappears, but you never see a puddle around it
like you would with regular ice!
Carbon dioxide has no liquid phase when the pressure on it is less than
about 5 times normal atmospheric pressure. So in the kind of pressure
that we like to live in, dry ice goes straight to gas when it melts. That kind
of behavior is called "sublimation", and we say that the dry ice "sublimes".
Every substance has some pressure limit like that. For water, it's 0.006 of
normal atmospheric pressure. At any pressure lower than that, liquid water
can't exist, and an ice cube sublimes ... it melts directly into water vapor
without a puddle.
When the electron wavefunction is bound in a stable state in an atom it stretches into a 'orbital' form. There was a mistake. When attached in a stable atomic state, an electron often acts like a three-dimensional oscillating wave, i.e. the orbital vibrates. It's sort of like a vibrating chord.
Answer: 4
Explanation: There are 4 valence electrons in group 14, the Carbon group.
Answer:
Dear Mr. President,
Your strong voice has called attention to the risks of human-induced climate change and the need to take timely and effective steps to address it. We are pleased to report further progress in our efforts to advise you on climate policy options that could help encourage these steps.
- (Explain what you learned in class today ) I don't know what you were taught in class so you have to figure what to put here.
Mr. President, our temperatures are consistently rising while moisture is increasingly evaporating. Forest management is merely one piece of the puzzle — something our own firefighters would be quick to remind you. Since 2009, our state has spent more than $130 million on forest health and fire preparedness. These events still overwhelm our residents and resources, because these fires are unlike anything people have seen before.
Sincerely,
Explanation:
hope this helps!
