Which will speed up a chemical reaction? apply heat. increase the concentration of the reactants. grind up the substance, so there is more surface area. all of the above

choosing tennis and golf balls is your inde choice.

their mass and volume are dep

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

i think the answer is a and b

i wish you luck