Answer:
0.13 g
Explanation:
mass of aluminum required = ( Dislocation length) / ( Dislocation density) × (density of metal)
3000 miles to cm ( 1 mile = 160934 cm) = 3000 miles × 160934 cm / 1 mile = 482802000 cm
density of Aluminium = 2.7 g /cm³
dislocation density of aluminum = 10¹⁰ cm³
mass of aluminum required = (482802000 cm × 2.7 g/cm³) / 10¹⁰ cm³ = 0.13 g
1) You need to use the atomic mass of copper.
You can find it in a periodic table. It is 63.546 amu.
2) The atomic mass is the weigthed mass of the different isotopes.
This is, the atomic mass of one element is the atomic mass of each isotope times its corresponding abundance:
=> atomic mass of the element = abundance isotope 1 * atomic mass isotope 1 + abundance isotope 2 * atomic mass isotope 2 + ....+abundance isotope n * atomic mass isotope n.
3) The statement tells there are two isotopes so the abundance of one is x and the abundance of the other is 1 - x
=> 63.546 amu = x * 62.9296 amu + (1-x)*64.9278
=> 63.546 = 62.9296x + 64.9278 - 64.9278x
=> 64.9278x - 62.9296 = 64.9278 - 63.546
=> 1.9982x = 1.3818
=> x = 1.3818 / 1.9982 = 0.6915 = 69.15%
=> 1 - x = 1 - 0.6915 = 0.3085 = 30.85%
Answer:
Cu-63 69.15%;
Cu-65 : 30.85%
Answer:
b) Baking soda
Explanation:
Baking soda is sodium hydrogen carbonate, NaHCO₃.
It reacts with water according to the equation
NaHCO₃ + H₂O ⇌ H₂CO₃ + NaOH
Thus, baking soda is a base because it increases the concentration of hydroxide ions in water.
<em>Water</em> is <em>neutral</em>.
<em>Lemon juice</em> is an <em>acid</em> because it contains citric acid.
An <em>insulator </em>is a substance that does not conduct electricity. Insulators are <em>neither acidic nor basic</em>.
