Classify blood as a mixture or a pure substance. if blood is a mixture, classify it as either heterogeneous or homogeneous. if blood is a pure substance, identify it as either an element or a compound.

Ions can have a positive or negative charge. false or true

Is air a element, compoud, or mixture.

Which of the following is not true? Newton's Laws include three laws about force and motion. An object will not change velocity unless acted upon by a force. Every action has an equal and opposite reaction.

A rectangular prism of volume 84 cm3 has a mass of 760 g. What is the density of the rectangular prism?

The molar mass of water (H2O) is 18.02 g/mol. Yun needs 0.025 mol H2O for a laboratory experiment. She calculates that she needs 72.0 g H2O for the experiment. Yun's calculation was incorrect because she set up her unit conversion incorrectly.

How many milliliters of a 0.7% stock solution are required to make 2 l of 0.2% solution? how many ml of solvent will be required to carry out the dilution?

What percentage of the naphthalene molecules emitted a photon?

In an endothermic reaction, heat is absorbed from the surroundings. How does this affect entropy? A. The particles in the surroundings move slower and have decreased entropy. B.

The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change that must happen at the molecular level? A. The molecules move more quickly and their average kinetic energy increases. B.

The most important reason why solid sodium hydroxide is not used as a primary standard is