Explanation:
5 I don't know what is the answer if I got it wrong
Answer:
As an example I can say sodium (Na) and chlorine (Cl).
Explanation:
An ionic bond occurs when a metal element reacts with a nonmetal element. Therefore in the answer given above the Na is metal and Cl is nonmetal and they form a molecule through ionic bonding.
Answer: The nuclide symbol of X is 
Explanation:
The given nuclear reaction is a type of alpha decay process. In this process, the nucleus decays by releasing an alpha particle. The mass number of the nucleus is reduced by 4 units and atomic number is also decreased by 2 units. The particle released is a helium nucleus.
The general equation representing alpha decay process is:
For the given equation :
As the atomic number and mass number must be equal on both sides of the nuclear equation:
Thus the nuclide symbol of X is
Answer is: 3,94 of hydrogen gas.
Chemical reaction: 2K + 2HBr → 2KBr + H₂.
n(K) = 9,87 mol.
n(H₂) = ?.
from reaction: n(K) : n(H₂) = 2 : 1.
9,87 mol : n(H₂) = 2 : 1
n(H₂) = 4,935 mol for 100% yield of reaction
n(H₂) = 4,935 · 0,798 = 3,94 mol for 78,9 % yield of reaction.
n - amount of substance
The boiling of water and sublimation of iodine crystals are endothermic processes.
Answer: Option B & C
Explanation:
Endothermic process are the classifications of chemical reactions where the heat is absorbed by the system from the surroundings. As the matters can exists in three phases like solid, liquid and gases.
The endothermic process occurs by absorption of heat energy by the system. So according to the given options, the boiling of water and iodine crystal sublimation follows endothermic process. In the boiling of water occurs when the water molecules absorb heat from the surrounding and convert to gas phase.
Similarly, the sublimation of iodine crystals also require heat energy from the surrounding to break the bonds of the iodine crystals to sublimate to gas phase. Thus the boiling of water and sublimation of iodine crystals are the examples of endothermic processes.
