Electrons are transferred in the formation of what kind of bonds?

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!