The atomic number of magnesium (Mg) is 12. This is also the number of which of the following?

A sound wave from a jackhammer travels through a section of concrete with a fixed frequency. At the concrete's boundary is mud. The diagram below shows the path of the sound wave as it travels from the concrete into the mud.

Calculate the average atomic mass of chlorine if 75.77% of its atoms have a mass of 34.97 amu and 24.23% of its atoms have a mass of 36.96 amu.

A scientist is testing an unknown sample of matter to determine its identity. He attempts to perform a chromatography experiment on the uniform sample but finds it to be inseparable.

The label on a bottle of vinegar indicates that it is 3.5% acetic acid (CH3COOH). If the density of the solution is 1.90 g/mL, what is the molarity of the solution?

Which type of reaction releases the greatest amount of energy per mole of reactant? (1) combustion (2) decomposition (3) nuclear fusion (4) oxidation-reduction

What is hydrocarbon?

Why did most scientists reject Wegner's theory for nearly a half century?

Define prediction and explain how it is used to formulate a hypothesis.

A group of organisms that breed and produce offspring that can breed. A. Species B. ecosystem C. Biodiversity

What is the molality of a solution containing 100 grams of glucose (C6H12O6, molar mass = 180 g/mol) dissolved in 2.5 kg of water? 0.22 m 72 m 7200 m 40 m