Which of these is an example of a chemical change?

Deflating a rubber balloon

Combining rubber with sulfur

Stretching an elastic rubber band

Erasing pencil marks from a page

What is one source of human stem cells other than embryos

How many moles does the mass quantity 127.4g of AgNO3 have?

What is the pH of 0.550 M H2 SO4

Choose the answer below that gives the correct chemical symbol and classification (metal, metalloid, or nonmetal) for the element named. Select one: a. The element called niobium is a metal with the chemical symbol Ni. b.

Rearrange D=m/v to make v the variable

Gasoline has a density of 0.749 g/mL. How many pounds does 19.2 gallons of gasoline weigh? Use significant figures. Do not enter "pounds" as part of your answer.

Which of these changes involved a physical change and not a chemical change?

Which of the following statements is true? Running an electric current through a magnet can create a magnetic field. Electric engines change electricity into magnetism. The strength of a magnetic field increases with distance.

valancy of x is 3 while that of y is 1. write a formula of the compounds when each of the seperaty combines with oxygen

The elements that contain electrons in an F sublevel near the highest occupied energy level are referred to as? A. Alkali metals B. Alkali earth metals C. transition metals D. inner transmission levels