20 points
the atomic symbol 206/82 pb represents lead-206 (pb-206), an isotope that has 82 protons and 124 neutrons. which atomic symbol could represent an isotope that undergoes radioactive decay to produce pb-206?
a) 238/92 u
b) 222/87 pb
c) 178/72 hf
d) 192/77 pb

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

Motivation cannot be developed with practice; a person either possesses it or they do not.

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.