The smallest unit of an element that maintains the properties of that element

A sample of fluorine-18 in a laboratory has an initial mass of 50mg. flourine-18 has a half life of 1.8 hours Calculate the amount of time it will take for the initial mass of fluorine-18 to be reduced from 59 mg to 12.5mg

Does a atom power a star

The electric motor has an input energy of 50,000 joules each second. The motor transfers 35,000 joules of useful energy each second. Calculate the efficiency of the electric motor (show workig out too)

A mass of 4.0 kg is in motion along a horizontal, frictionless surface with a speed of 2.5 m/s when it makes contact with a horizontal spring anchored to a wall. The spring compresses and brings the mass to a momentary rest.

2. For the following questions, use a periodic table and your atomic calculations to find the unknown information about each isotope: You have a Helium Isotope with 2 neutrons. How many electrons are there? 0 2 4 6

You measure a watch's hour and minute hands to be 7.4 mm and 12.1 mm long, respectively. Part A In one day, by how much does the distance traveled by the tip of the minute hand exceed the distance traveled by the tip of the hour hand?

Describe the possible long term impact of a catastrophic event

Calculate the mass defect of the helium nucleus 42He. The mass of neutral 42He is given by MHe=4.002603u.

A transparent film laminated to a fabric is identified in the study material as a. stretch fabric. b. PVC. c. a skin. d. two-faced fabric

Technician A says that all friction and steel plates in a clutch pack should be replaced during and overhaul. Technician B says that the automatic transmission fluid cooler should always be flushed when a unit is rebuilt or replaced.