Taking a nap in the afternoon makes people more focused for the rest of the day

The density of ethanol is 0.789g/ml at 20°c. find the mass of a sample of ethanol that has a volume of 150.0 ml at this temperature.

1. Salts consist of atomic particles that have an (blank) charge. fill in the blank 2. The metallic atoms have a positive charge, while the nonmetallic atoms have a (blank) charge.

When Rutherford's coworkers bombarded gold foil with a particles, they obtained results that overturned the existing (Thomson) model of the atom. Explain.

37.0 °C = °F (human body normal temperature)

How much energy would it take to heat a section of the copper tubing that weighs about 630.0 g, from 13.12 ∘C to 27.91 ∘C? Copper has a specific heat of 0.3850 (J/g) ⋅∘C. Express your answer to four significant figures.

When metals react with nonmetals, an ionic compound generally results. what is the predicted general formula?

Why could the Bohr model not predict line spectra for atoms other than hydrogen?

Cryolite, Na3AlF6 (s), an ore used in the production of aluminum, can be synthesized using aluminum oxide. Balance the equation. 1.) Balance the equation - AlO3 (s) + NaOH (l) + HF (g) - ->Na3AlF6+H2O (g) 2.) If 17.5 kilograms of Al2O3 (s), 51.

The volume, in liters, of 538 g of CO2

What are two types of cold air masses that influence the weather in North America? Name them and describe their humidity.