Answer: The p orbital can hold up to six electrons. We'll put six in the 2p orbital and then put the remaining electron in the 3s. Therefore the sodium electron configuration will be 1s22s22p63s1.
Explanation:
You will need a periodic table to help you answer this problem. The atomic numbers are arrange from lowest to highest in the periodic table. You can locate element number 55 to be Cesium with an atomic weight of 132.905 amu. So, you start from element 56. The following elements are:
56 Barium 137.328 amu
57 Lanthanium 138.905 amu
58 Cerium 140.116 amu
59 <span>Praseodymium 140.908 amu
60 Neodymium 144.243 amu
Neodymium is already greater than 144 amu. Therefore, these elements only include Barium, Lanthanium, Cerium and Praseodymium.</span>
Answer:
Length of a rectangle whose width is 4 inches is
<u>6 inches</u>
Explanation:
Ratio of length to its width is 3 to 2
Let length = L
Let Width = B
L: B = 3 : 2 (given)

Width ,B = 4
Insert B in above equation


cross multiply,

L = 6 inches
Conversion(if required) ,
1 inch = 2.54 cm
6 inch = 2.54 (6)
L = 15.24 cm
1. Answer;
- Exothermic reaction
Explanation;
-Exothermic reactions are types of chemical reactions in which heat energy is released to the surroundings. Since enthalpy change is the difference between the energy of products an that of reactants. It means that in an exothermic reaction the energy of products is less than that of products. In this case an energy of 315kJ is released to the surroundings.
2. Answer;
Conserved
-The total amount of energy before and after a chemical reaction is the same. Thus, energy is conserved.
Explanation;
-According to the law of conservation of energy, energy is neither created nor destroyed. Energy may change form during a chemical reaction. For example, energy may change form from chemical energy to heat energy when gas burns in a furnace. However, the exact amount of energy remains after the reaction as before, which is true for all chemical reactions.