A 60.0-g sample of fermium-253 was placed in a sealed vessel 9.0 days ago. Only 7.5 g of this isotope is now left. What is the half-life of fermium-253?

Which type of radiation travels as an electromagnetic wave? * a) alpha particle b) beta particle c) gamma ray d) X-ray

The hydrogen atomic emission spectrum includes a UV line with a wavelength of 92.3 nm. Is this line associated with a transition between different excited states or between an excited state and the ground state?

Methanol can be synthesized by combining carbon monoxide and hydrogen. co (g) + 2h 2 (g) ch 3oh (g) δ h° rxn = - 90.7 kj a reaction vessel contains these compounds at equilibrium.

Highest ionization energy: Li, Be, B

Based on its location in the periodic table, which of these is a property of nickel? A Low density B Strong semi conductor C Highly reactive with other elements D Good conductor of heat and electricity

10) A screwdriver has the density of 5.5 grams per cubic centimeter. It also has the mass of 2.3 grams. What is the screwdriver's volume?

A chemist weighed out 20.7 g of sodium. Calculate the number of moles of sodium she weighed out

If 1.00 mol of argon is placed in a 0.500-L container at 20.0 ∘C, what is the difference between the ideal pressure (as predicted by the ideal gas law) and the real pressure (as predicted by the van der Waals equation) ? For argon, a=1.

Part 2: Finding Speed and Height Using Energy Directions: Use the KE and GPE equations to solve for speed or height depending on the situation. 1. A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed? 2.

Why is conductivity be the best test to find a metal, non-metal or metalloid?