If a 900.0-g sample of radium-226 decays to 225.0 g of radium-226 remaining in 3,200 years, what is the half-life of radium-226?

How many resonance structures does NH₃ have?

Consider a 1.0-l flask containing neon gas and a 1.5 l flash containing xenon gas. both gases are at the same pressure and temperature. according to avogadro's law, what be said about the ratio of the number of atoms in the two flasks?

How does algal growth caused by agricultural waste kill marine organisms? A. By blocking sunlight and depleting oxygen. B. By increasing oxygen levels in the water. C. By maintaining balance in the water D.

Which of these can be considered a system? Check all that apply.

Which substance is amphiprotic?

The rate constant for the decomposition of acetaldehyde, CH₃CHO, to methane, CH₄, and carbon monoxide, CO, in the gas phase is 1.32 ✕ 10⁻² L/mol/s at 707 K and 3.20 L/mol/s at 851 K. Determine the activation energy (in kJ/mol) for this decomposition.

Northern China experienced drought and southern China had floods in 1997 following warmer-than-average water temperatures in the eastern Pacific Ocean. What likely caused these weather events? A. The jet stream B. La Niña C. An occluded front D.

Would the local wind change if it was nighttime

Does the radius of magnesium increase or decrease as it loses electrons?

Rachel is given 50 grams each of three different white powders that look very similar. She is told that each of these powders is commonly used in cooking. Without tasting any of them, she is asked to try to identify them.