The half-life for 1850s is about 94 days. Which of the following reasons best explains why NAA is not a convenient method to obtain this value?1. Os is an expensive metal and is not suitable for radioactive measurements. 2. Os is too intensely radioactive to handle safely in an NAA apparatus. 3. The Os half-life is too long to be measured conveniently. 4. NAA is less accurate for metallic elements such as Os.

Select the correct answer from each drop-down menu.describe what happens to a carbon-11 atom when it undergoes positron emission.the decay of a carbon-11 atom _1_, and this causes it to emit _2_.options for 1: > changes a neutron into a proton> changes a proton into a neutron> is hit with a neutron> reconfigures its protons and neutronsoptions for 2: > a negatively charged electron-sized particle> a positively charged election-sized particle> two atoms and several neutrons> two neutrons and two protons

Which of the following statements about hybrid orbitals is or are true? choose all that apply. choose all that apply. under sp2 hybridization, the large lobes point to the vertices of an equilateral triangle. after an atom undergoes sp hybridization there is one unhybridized p orbital on the atom. the angle between the large lobes of sp3 hybrids is 109.5∘

Chromosome 17 is made of over million base pairs.