Which of the following is an example of a chemical change?

Gasoline evaporating.

A ice cube melting.

Toasting a marshmallow.

Mixing sugar and water.

Lars is balancing equations with his study group. He is unsure about one equation because each member of the study group came up with a different answer.

How can a scientist ensure that his or her data are reliable? by making a single observation by repeating trials during an experiment by recording values without units by keeping the results private

Metallic bonding occurs between atoms of

The atomic number of an atom is always equal to the number of its (1) protons, only (2) neutrons, only (3) protons plus neutrons (4) protons plus electrons

Luke recorded his results in a table as shown below. beaker volume of water, in cm3 temperature at start, in °C temperature after 2 minutes, in °C A 25 18 30 B 50 18 24 C 75 18 22 (a) Why did Luke need to know the temperature of the water at the

To what decimal place should each answer be rounded how many significant figures does the rounded answer have 9 cm + 2.8 cm = 11.8 cm

Wasser and water are examples of cognates. True or False

Write the net ionic equation, including the phases. 2hbr (aq) + ba (oh) 2 (aq) - - - > 2h2o (l) + babr2 (aq)

A student needs to prepare 50.0 mL of a 1.30 M aqueous H2O2 solution. Calculate the volume of 5.0 M H2O2 stock solution that should be used to prepare the solution.

Which of the following is the best name for a compound made from nitrogen and oxygen? (N2O3) nitrogen oxide nitrogen II oxide nitrogen trioxide dinitrogen trioxide