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Answer:
Ionic substance
Explanation:
An ionic substance is formed when oppositely charged ions link up to form an infinitely large lattice structure that can only be described in terms of unit cells.
Ionic substances may consist of billions of oppositely charged ions. Ionic substances are hard, have high melting and boiling points and do not conduct electricity in the solid state because the ions are not free in the solid state.
However, in solution or molten state, the substance conducts electricity since the ions which are the charge carriers are now mobile.
Polyethene is a polymer composed of repeating units of the monomer ethene.
The properties of polyethene are as follows:
- density- ranges 0.857 g/cm3 to 0.975 g/cm3.
- specific heat capacity is 1.9 kJ/kg.
- melting temperature is approximately 110 °C.
<h3>What are polymers?</h3>
Polymers are large macromolecules consisting of long repeating chains of smaller molecules known as monomers.
An example of a polymer is polyethene composed of repeating units of the monomer ethene.
The density of polyethylene ranges 0.857 g/cm3 to 0.975 g/cm3.
The specific heat capacity of polyethene is 1.9 kJ/kg.
The melting temperature of polyethene is approximately 110 °C.
Learn more about polyethene at: brainly.com/question/165779
Answer:
5.625 moles of oxygen, O₂.
Explanation:
The balanced equation for the reaction is given below:
4Al + 3O₂ —> 2Al₂O₃
From the balanced equation above,
4 moles of Al reacted with 3 moles of O₂.
Finally, we shall determine the number of mole of O₂ required to react with 7.5 moles of aluminum, Al. This can be obtained as illustrated below:
From the balanced equation above,
4 moles of Al reacted with 3 moles of O₂.
Therefore, 7.5 moles of Al will react with = (7.5 × 3)/4 = 5.625 moles of O₂.
Thus, 5.625 moles of O₂ is needed for the reaction.
There are two naturally occurring isotopes of gallium: mass of Ga-69 isotope is 68.9256 amu and its percentage abundance is 60.11%, let the mass of other isotope that is Ga-71 be X, the percentage abundance can be calculated as:
%Ga-71=100-60.11=39.89%
Atomic mass of an element is calculated by taking sum of atomic masses of its isotopes multiplied by their percentage abundance.
Thus, in this case:
Atomic mass= m(Ga-69)×%(Ga-69)+X×%(Ga-71)
From the periodic table, atomic mass of Ga is 69.723 amu.
Putting the values,
Thus,
Rearranging,
Therefore, mass of Ga-71 isotope is 70.9246 amu.
