Weathering and chemical substance weathering
You spelled calendar incorrectly, the correct spelling is the one I previously wrote...Calendar
A physical change doesn't change what the substance is but for chemical change a new substance is formed and energy is either given off or absorbed.
Answer:
Because X-rays have wavelengths similar to the size of atoms
A polar covalent bond is a covalent bond in
which the atoms have an unequal attraction for
electrons and so the sharing is unequal. ... The
atom with the greater electronegativity acquires
a partial negative charge, while the atom with
the lesser electronegativity acquires a partial
positive charge.
here you go