Which type of radioactive emission has a positive charge and weak penetrating power?
(1) alpha particle (3) gamma ray
(2) beta particle (4) neutron

Why is the melting of ice a physical change ?

Which of the following would not diffuse through the plasma membrane by means of simple diffusion? 1 oxygen 2 glucose 3 a steroid hormone 4 a lipid soluble vitamin

Which statement characterizes synthetic polymers? a. they come from animals and plants. b. they are found in nature. c. they are made in a lab. d. they are components of starch.