4. Methods scientists use to determine if a change was physical or chemical

Why do some salts dissolve spontaneously even though the process is endothermic overall?

Which process can you blame if you burn your finger on a metal utensil sitting in a pot of extremely hot water

Which word in the sentence is the predicate adjective? The glowing red coals looked incredibly hot. A. red B. hot C. glowing D. incredibly

1. What percent of light passes through the sample if its absorbance A=2? 2. For the best calibration curve, the transmittance values (%T) should fall within the range from 10% to 90%.

A sample that is 74.5 percent chloride by mass is dissolved in water and treated with an excess of AgNO3. If the mass of the AgCl precipitate is 1.115 g, what was the mass of the original sample?

Think about a neutral magnesium atom. Then think of a magnesium ion with a 2+charge. How are these two alike? How are they different? Be sure to use the terms proton, neutron, and electron in your answer.

What subatomic particle is specifically responsible for combining the atoms together to form a new substance?

A chemist reported that 100 gallons of a gas were available in a laboratory. Which property of the gas did the chemist report?

Is the water density higher than the aluminum density

How many moles of molecular oxygen (o2) are consumed in the complete combustion of one mole of pentane (c5h12) ?