The answer is b. radon-222. The alpha decay means that it will emit an alpha particle when decays. The alpha particle has two protons and two neutrons. So Radium(88) minus two protons will become Radon(86). And the atomic mass will become 226-4=222.
The answer is (1).
Quantum mechanics views electron orbitals not as fixed circular paths or defined boundaries, but as probablility distributions that represent the probability of finding an electron at any point in space around the nucleus. For simplicity, discrete "boundaries" are often drawn enclosing the area where electrons should be found 90% of the time.
Answer:
a tough, light, flexible synthetic resin made by polymerizing ethylene, chiefly used for plastic bags, food containers, and other packaging.
Explanation:
Lithosphere, asthenosfhere , lower mantle