the alpha decay of a radioactive nuclide (x) emits a he-4 nucleus and produces an isotope of 235/92 u, what is x?
a. 235/91 pa
b. 235/93 np
c. 236/92 u
d. 239/94 pu

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?