Look at this description of the sun. Are the following descriptions of the sun chemical or physical properties? 1. The sun is a huge ball of hot spinning gases.

2. The sun has dark magnetic fields called sun spots.

3. The sun causes solar winds.

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Ionic compounds are made of ions, and yet the overall charge of an ionic compound is neutral. why?