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 th

half-life of fermium-253?

3.0 days

4.5 days

17.5 days

20.0 days

Why does a higher concentration make a reaction faster? There are more collisions per second and the collisions are of greater energy. Collisions occur with greater energy. There are more collisions per second.

What element is used for shiny trim on cars

Which pair of ions can form an ionic bond with eachother and why

A student performs an experiment to see how catalysts affect the rate of a reaction. He notices that when the reaction is nearly finished, it stops bubbling. He wants to know how much faster the reaction occurs when a catalyst is used.

Given only the following data, what can be said about the following reaction? 3H2 (g) + N2 (g) - --> 2NH3 (g) ΔH=-92kJ A.) The enthalpy of products is greater than the enthalpy of reactants B.

What would happen if you tried to sqeeze a gas into a smaller container?

Paint, paint thinners and some cleaning agents can weaken the shell of a hard hat and may eliminate

A 10 chunk of metal has a specific heat of 0.25 J/g ºC. The temperature is changed from 10ºC to 45ºC. How much heat is required?

In this reaction what is the correct coefficient for sodium chloride? pb (no3) 2? nacl → pbcl2? nano3

Classify each of the following as a path function or a state function. work energy distance traveled enthalpy heat