Which of these is an example of a chemical change

f. methane is burned in air.

g. solid gold is melted to make jewelry.

h. a bar of copper is stretched into a long copper wire.

j. iron is coated with bronze to prevent rusting.

Determine the concentration of a solution prepared by diluting 20.0 ml of a 0.200 m rbcl to 250.0 ml. determine the concentration of a solution prepared by diluting 20.0 ml of a 0.200 m rbcl to 250.0 ml. 0.00800 m 0.160 m 0.0160 m 0.0320 m 2.50 m

Inside stars in space, the nuclei of hydrogen atoms fuse together to form helium atoms. This represents which form of energy?

While hiking in Costa Rica, Bert discovers a new species of arthropod. Which characteristics should he look at to determine in which group it belongs?

What is the ph of a solution if [oh-] = 2.3 x 10-5 m?

A flame ionization detector a. uses electrons to create ions b. uses a flame to remove an electron from an analyte c. uses a flammable liquid and oxygen to produce a flame d. uses an electric filament to ionize molecules e.

How can scientists study the composition of distant stars?

When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e. g.

From A complete stop a car reaches a velocity of 280 KM/S east in 7 seconds what is the rate of acceleration? A. 4 KM/S B. 7 KM/S C. 40 KM/S D. 70 KM/S

How sand is deposited along coastline

How do the reaction rates change as the system approaches equilibrium?