Answer:
b. The shorter the half-life, the more dangerous the radioisotope.
Answer: d
explanation: in both reactants and products there are 2 hydrogen and 2 chlorine atoms
C.) Action force unless it has potential/stored enerygy
The answer is 2 electrons.
The electron configuration of calcium is 2:8:8:2
Calcium has two electrons in its outermost shell. These are its valence electrons and are the ones used in bonding with other elements. Valence electrons of an atom are those electrons that are in its outer energy shell or that are available for bonding.
Calcium is a metal. When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms forming ions. The resulting compound is known as an ionic compound.
For example, when calcium metal reacts with chlorine gas, calcium gives up its two valence electrons and Chlorine accepts them resulting in a new substance called calcium chloride in which the two elements have ended up forming ionic bonds.
Answer: Option (4) is the correct answer.
Explanation:
It is known that density is mass divided by volume.
Mathematically, Density = 
Since, density is directly proportional to mass. So, more is the mass of an element more will be its density.
Mass of magnesium is 24.305 g/mol.
Mass of barium is 137.327 g/mol.
Mass of beryllium is 9.012 g/mol
Mass of radium is 226 g/mol.
Hence, radium has more mass therefore it will have the greatest density at STP.
