Answer:
alkali metals hydrogen lithium sodium potassium rubidium cesium francium alkaline earth metals beryllium magnesium calcium strontium barium radium group 3 boron aluminium gallium indium thalium carbon family carbon silicon germanium tin lead
Explanation:
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Answer:
jet streams
Explanation:
THE JET STREAM Narrow bands of exceedingly high speed winds are known to exist in the higher levels of the atmosphere at altitudes ranging from 20,000 to 40,000 feet or more. They are known as jet streams.
Answer:
ΔH = -55.92 kJ
Explanation:
<u>Step 1:</u> Data given
1 mol NaOH and 1 mol HBr initially at 22.5 °C are mixed in 100g of water
After mixing the temperature rises to 83 °C
Specific heat of the solution = 4.184 J/g °C
Molar mass of NaOH = 40 G/mol
Molar mass of HBr = 80.9 g/mol
<u>Step 2: </u>The balanced equation
NaOH + HBr → Na+(aq) + Br-(aq) + H2O(l)
<u>Step 3:</u> mass of NaOH
Mass = moles * Molar mass
Mass NaOH = 1 * 40 g/mol
Mass NaOH = 40 grams
Step 4: Mass of HBr
Mass HBr = 1 mol * 80.9 g/mol
Mass HBr = 80.9 grams
Step 5: Calculate ΔH
ΔH = m*c*ΔT
ΔH= (100 + 40 + 80.9) * 4.184 * (83-22.5)
ΔH= 220.9 * 4.184 * 60.5
ΔH= 55916.86 J = 55.92 kJ
Since this is an exothermic reaction, the change in enthalpy is negative.
ΔH = -55.92 kJ
(i) 1 mole of Ar =6.022×10^23
atoms of Ar
52 mol of Ar=52×6.022×10 ^23
atoms of Ar =3.131×10 ^25 atoms of Ar
(ii) Atomic mass of He = 4amu
Or
4amu is the mass of He atoms = 1
Therefore 52 amu is the mass of He atoms=0.25×52=13 atoms of He
(iii) Gram atomic mass of He = 4g
Or
4g of He contains =6.022×10 ^23
atoms
Therefore 52 g of He contains=
6.022×10 ^23/4×52 =7.83×10 ^24 atoms
Answer:
Iron is the densest out of the given options.
Explanation:
Oxygen
1.429 g/L
Water
1000 g/L
Hydrogen Peroxide
1450 g/L
Iron
7874 g/L
Iron Oxide
5240 g/L
