So our professor didn't go over this but is freshly cut sodium, but rapidly tarnishes on contact with air a physical or chemical property?

Hey!

After the slight confusion (haha)...

Your answer should be a CHEMICAL CHANGE / PROPERTY

Explanation:

Its CHEMICAL because the sodium has reacted with the air (oxygen in technical terms) which then forms SODIUM OXIDE...the tarnishing of the cut sodium surface it a thin layer of the SODIUM OXIDE...

HOPE THIS HELPED!

answer: option (b) is the correct answer.

explanation:

a covalent bond is formed by sharing of electrons. whereas polarity arises due to difference in electronegativity of two atoms.

therefore, more is the electronegativity of an atom which combines with the titanium, more readily it will induce a partial positive and negative charge.

thus, out of the given options fluorine is most electronegative and has an incomplete octet. therefore, it will readily combine with titanium to share the electrons and complete its octet.  

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

: )