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.

Which term best describes the form sound takes as it travels away from a drum (a- gas)(b-music) ( c-waves) (d-particles

Si una estrella no tiene paralaje medible, ¿qué puedes inferir?

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