In a chemical reaction, atoms are created or destroyed. true or false user: heat, gas production, and color change can all be evidence of chemical change. true or false

A student dissolves a substance in water, tests the resulting solution, and observes that red litmus paper turns blue. based on this result, the solution is

3. What is the relationship between the kinetic energy of gas particles and the temperature of the gas?

Can a centigram balance be read to the nearest milligram?

Over the past one thousand years, the temperature of the earth has consistently risen, with every year recording a higher temperature than the previous year. True or False?

Determine the pH of a 0.350 M solution of HA. The pkb of A - is 12.830.

You want to create 14.0 g of copper to meld into a piece of jewelry. You know that when copper (II) chloride reacts with aluminum, copper is a product. How much aluminum would you need to start your reaction with to get 14.

What happens to electronegativity values when moving from left to right across the period in the periodic table

A 27.40 g sample of liquid mercury is initially at 158.30°C. If the sample is heated at constant pressure ( = 1 atm), kJ of energy are needed to raise the temperature of the sample to 376.20°C. How much energy in kJ is required?

When a sample of gas is cooled, it condenses into a liquid. In which of the following ways do the molecules of the original gas sample compare with the molecules of the liquid? a. The molecules weigh less as a gas than they do as a liquid. b.

In a group 1 analysis, a student obtained a precipitate containing both AgCl and PbCh. Which of the following reagents would enable separation of AgCl (s) from PbCl (s) ? O Hys 0 Na2CO3 o KOH O NH3 O