1
An atom.......
➔ is the smallest unit of matter that retains the properties of an element.
What is nucleon?
Nucleons = protons + neutrons
They make up almost all the mass of an atom.
•Which element has 53 electrons?
Iodine (I).
•Which element has 30 neutrons?
Fe-56
If an atom loses one electron.....
•there is one electron fewer than the number of protons (charge of +1)- cation
Calculate an electron capacity for n4(N) shell
2n2
2*42=32
Give Simple explanation of Principal Quantum Number (n).
Main energy level (or shell) where an electron is found in an atom.
.......tells us the orientation of an orbital in space within a given subshell.
magnetic quantum number
(l = 0) → 1 orbital
p (l = 1) → mₗ = −1, 0, +1 → 3 orbitals
d (l = 2) → 5 orbitals
f (l = 3) → 7 orbitals
Aufbau principle-
“lower energy orbitals will fill before higher energy ones”
What is Chemical bonds?
•The force that holds atoms together
Why some elements are inert?
Because of Octate rule
Identify the types of chemical bonds present in the compounds calcium chloride and ammonia
Ionic, Covalent
Tell oxidation state of Sulfur in the given compound Al2(SO4)3, H2S, H2S2O7
6+, 2-,6+
Continue and balance the reactions.
1. AgNO3(aq)+Na2CO3(aq)→
2. NaHCO3+HCl→
2AgNO3(aq)+Na2CO3(aq)→Ag2CO3(s)+2NaNO3(aq)
NaHCO3+HCl→NaCl+CO2+H2O
..... is a way to describe the chemical ratios of the atoms that make up a specific chemical compound or molecule in chemistry.
A chemical formula
How many electrons are present in the Mg²⁺,Cl⁻, Al³⁺ ions?
10, 18, 10
Question:20.0 mL of 0.1 M NaOH is used in a titration. How many moles of NaOH were used?
Moles=M×V(L)=0.1×0.020=0.002 mol
Question:
25.0 mL of 0.2 M HCl neutralizes 1.50 g of a solid base X. The reaction is:
X+HCl→XCl+H2OX + HCl → XCl + H_2OX+HCl→XCl+H2O
Calculate the molar mass of X.
n=M×V=0.2×0.025=0.005 mol
Moles of X = 0.005 mol (1:1 ratio)
Molar mass of X:
M=MassMoles=1.500./005=300 g/molM = = \frac{1.50}{0.005} = 300 \text{ g/mol}M=MolesMass=0.0051.50=300 g/mol
Question:
25.0 mL of NaOH solution is required to neutralize 20.0 mL of 0.1 M HCl in a titration. The reaction is:
NaOH + HCl → NaCl + H₂O\text{NaOH + HCl → NaCl + H₂O}NaOH + HCl → NaCl + H₂O
Calculate the molarity of the NaOH solution.
n=M×V=0.1×0.020=0.002 mol
From the reaction, 1:1 ratio → moles of NaOH = 0.002 mol
Volume of NaOH = 25.0 mL = 0.025 L
Molarity of NaOH:
M=nV=0.0020.025=0.08 MM = \frac{n}{V} = \frac{0.002}{0.025} = 0.08 \text{ M}M=Vn=0.0250.002=0.08 M
Question:
A solution has a hydrogen ion concentration [H⁺] = 1 × 10⁻³ M. What is the pH of the solution?
pH=−log[H+]=−log(1×10−3)=3