Answer ; The question is missing in some details, but here are he details ;
The two naturally occurring isotopes of bromine are
81Br (80.916 amu, 49.31%) and
79Br (78.918 amu, 50.69%).
The two naturally occurring isotopes of chlorine are
37Cl (36.966 amu, 24.23%) and
35Cl (34.969 amu, 75.77%).
Bromine and chlorine combine to form bromine monochloride, BrCl.
Explanation:
The detaile calculation is as shown in the attachment.
For metals, reactivity increases down a group and from right to left across a period. Non metals, reactivitt increases up a grouo and from left to right across a period. Francium is the most reactive metal and fluorine is the most reactive non-metal.
Answer:
The answer to your question is below
Explanation:
Propane = C₃H₈
Process
1.- Write the chemical reaction
C₃H₈ + O₂ ⇒ CO₂ + H₂O
balanced chemical reaction
C₃H₈ + 5O₂ ⇒ 3CO₂ + 4H₂O
Reactants Elements Products
3 C 3
8 H 8
10 O 10
b) Standard enthalpy
Propane -104.7 kJ/mol
Oxygen 0 kJ/mol
Carbon dioxide -393.5 kJ/mol
Water -241.8 kJ/mol
ΔH° = ∑ΔH° products - ∑H° reactants
ΔH° = 3(-393.5) + 4(-241.8) - [(-104.7) + 0]
-Simplification
ΔH° = -1180.5 kJ/mol - 967.2 kJ/mol + 104.7 kJ/mol
ΔH° = - 2042.5 kJ/mol
This reaction is exothermic because ΔH° is negative.
The position of a given element in the periodic table depends on the atomic number. Further the atomic number is equal to the number of protons and the number of electrons of the particular element.
Also for the considered element, depending on the atomic number, the placement in the periodic table will create groups (columns) and periods (rows).
As a example we will take two atoms carbon (C) and nitrogen (N):
carbon (C) - has a atomic number of 6, it contains 6 protons and 6 electrons, and you find this element in the group 14 and period 2 in the periodic table
nitrogen (N) - has a atomic number of 7, it contains 7 protons and 7 electrons, and you find this element in the group 15 and period 2 in the periodic table