The valence electrons are the one furthest from the nucleus
Think of it like this, gravity has to pull harder on the heavier object to make them fall at the same rate , but doesn't have to pull as hard for the lighter object , thus is why sometimes heavier objects fall faster then lighter ones
Answer:
lead with Z = 82 is transformed into Bismuth with Z = 73
The Po with Z = 84 becomes Pb with Z = 82
Explanation:
Beta decay occurs when a neutron emits an electron and an anti neutrino from the atomic nucleus, therefore the atomic number of the material increases by one unit.
Pb + e + ν → Bi
lead with Z = 82 is transformed into Bismuth with Z = 73
In alpha decay, a helium nucleus is emitted from the nucleus of the atom, therefore the atomic number decreases by two units.
Po +α → Pb
The Po with Z = 84 becomes Pb with Z = 82
<span>A. Copper is a good conductor of electricity because its atoms have a loosely held electron in their outer shell that is able to move freely to other atoms.</span>
Answer:
1. Recollapsing universe
2. Critical universe
3. Coasting universe
Explanation:
Recollapsing universe has dark matter density greater than critical density. While critical universe has its matter density equal to the critical sensity. Coasting universe on the other hand has much smaller matter density compared to critical density.
Note that the critical density is approximately 10^-20 grams/cm3
