Primarygun

Why the gamma ray and X-ray emitted by the sun does not affect our life much?

Thank you very much. What is a probable reason for this observation? Sound wave travel slower in CO2 than air only? How about other gases, such as Hydrogen?

I'd think we are more unscrupulous to people, to the nature.

Why the amplitude of a wave increases when it passes from shallow region to deep region?

Ammonia has a simple molecular structure. Moreover, it is a gas. It vibrates faster than the water molecules and the attractive force is not very strong enough, so they easily escape.

Sound waves are longitudinal waves.

Is it very pure?

I don't know. Someone told me that it travels faster in air.

Which of the sound wave travels at a higher speed? In air, In carbon dioxide.

Comment on this sentence. A more reactive element forms a more non-reactive compound. Stable is better than NON-reactive?

If there are two salts in a solution, evaporating the water slowly to boil the water away, two kinds of crystals are formed. Why the each of the crystals is not contaminated by the other salt,like staying in the "core" of the crystal?

Then, it is more reactive than Cu(OH)2? But to get K by reducing, electrolysis is needed, why? but to get Cu, carbon is needed only.

Then, why?????:"?

The plane that is perpendicular to plane VDHB is VFH?

So a more reactive metal forms a more stable compound only comes true when the compound is not in water?

Which one's solubility in water is higher? KOH, NaOH.

K2O(s) is really so dangerous with HCl? My book said the rate of KOH(aq)+HCl and NaOH(aq) + HCl is more or less the same, is it correct? I have some anhydrous powder. It is a calcium compound. How I can distinguish calcium oxide and calcium hydroxide?

so what is the projection in your method of F? Projection of a point on a plane refers to the line joining the point and the projection(a point) is perpendicular to all line passing through the plane. what's the distance from the point F to that plane>?

Which of the following reaction is more vigorous? K2O + HCl, Na2O + HCl. I know that the rate of KOH+HCl and NaOH + HCl is more or less the same.

What softwares do you suggest?

My method: Draw a line perpendicular from F to BH at I. Extention of BH may be needed. Then, Draw a perpendicular line from BH in the plane BVDH. Name the line IZ. Then, draw a line perpendicular from F to IZ cut at P. Then, P is the projection. Is this a correct method? Wait a minute, I show you the picture in order to help you to get fully understood.

adding HNO3 in HCl would lower its pH value/?

I don't need a quick hint, just do it in your leisure time. Your reply inspire really much. If you don't reply, I think I will probably forget it in 1-2 days.

Frequency does not change.

If a wave passed from a shallower region into a deeper region, will its amplitude increase?