Heat flows from high temperature to low temperature
Answer: a. alpha emission : atomic number decreases by 2 units and mass number decreases by 4 units.
b. beta emission : atomic number increases by 1 unit and mass number remains same.
c. gamma emission : atomic number and mass number both remain same.
Explanation:
1. Alpha emmision: In this process, alpha particles is emitted when a heavier nuclei decays into lighter nuclei. The alpha particle released has a charge of +2 units, thus atomic number decreases by 2 units and mass number decreases by 4 units.
![_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}+_2^4\alpha](https://tex.z-dn.net/?f=_Z%5EA%5Ctextrm%7BX%7D%5Crightarrow%20_%7BZ-2%7D%5E%7BA-4%7D%2B_2%5E4%5Calpha)
2.)Beta-emmision: In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units, thus atomic number increases by 1 unit and mass number remains same.
![_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_{-1}^0\beta](https://tex.z-dn.net/?f=_Z%5EA%5Ctextrm%7BX%7D%5Crightarrow%20_%7BZ%2B1%7D%5EA%5Ctextrm%7BY%7D%2B_%7B-1%7D%5E0%5Cbeta)
3.) Gamma ray emission: in this process, an unstable nuclei gives off excess energy by a spontaneous electromagnetic process and releases
. These radiations does not carry any charge and are electrically neutral, thus atomic number and mass number both remain same.
![_Z^A\textrm{X}^*\rightarrow _Z^A\textrm{X}+_0^0\gamma](https://tex.z-dn.net/?f=_Z%5EA%5Ctextrm%7BX%7D%5E%2A%5Crightarrow%20_Z%5EA%5Ctextrm%7BX%7D%2B_0%5E0%5Cgamma)
Answer:
Molarity = 1.23 M
Explanation:
Given data:
Molarity of NaCl = ?
Mass of NaCl = 89.94 g
Volume of solution = 1249 mL ( 1249/1000 = 1.249 L)
Solution:
First of all we will calculate the number of moles of NaCl.
Number of moles = mass/molar mass
Number of moles = 89.84 g/ 58.5 g/mol
Number of moles = 1.54 mol
Molarity:
Molarity = Number of moles of solute / volume of solution in L
Molarity = 1.54 mol / 1.249 L
Molarity = 1.23 M