All the isotopes of plutonium has 94 protons and 94 electrons. For the number of neutrons of a specified isotope: number of neutrons = rounded atomic mass of the isotope-atomic number (or protons number).
Canada thistle can be killed with either Roundup or 2,4-D weed killers. These weed killers will kill back the leaves on the plant and will kill back some of the root system. The best time to apply these weed killers is on sunny days when the temperatures are between 65 and 85 degrees F. (18-29 C.).hese weed killers will kill back the leaves on the plant and will kill back some of the root system. The best time to apply these weed killers is on sunny days when the temperatures are between 65 and 85 degrees F. (18-29 C.).
Other Ways to Kill Weeds. 1  1. Use salt as a weed killer. Try this method only if you want to eradicate weeds in an area where you do not plan to grow anything for several years -- perhaps around paving stones and in pavement cracks. 2  2. Kill the weeds with boiling water.