Answer:
Use the following answers for questions 1 - 2. (1984 - #8 & 9)
(A) A network solid with covalent bonding
(B) A molecular solid with zero dipole moment
(C) A molecular solid with hydrogen bonding
(D) An ionic solid
(E) A metallic
The answer is: D.unstable nuclei emitting high-energy particles as they formed more stable compositions.
Those high-energy particles are alpha particles
, beta particles
, gamma radiation.
For example, the decay chain of ²³⁸U is called the uranium series.
Decay start with U-238 and ends with Pb-206. There are several alpha and beta minus decays.
Antoine Henri Becquerel (1852 – 1908) was a French physicist and the first person to discover evidence of radioactivity.
Becquerel wrapped fluorescing crystal (uranium salt potassium uranyl sulfate) in a cloth, along with the photographic plate and a copper Maltese cross.
Several days later, he discovered that a image of the cross appeared on the plate.
The uranium salt was emitting radiation.
Because of this discovery, Becquerel won a Nobel Prize for Physics in 1903, which he shared with Marie Curie and Pierre Curie.
<span>A homogeneous mixture that does not settle out upon standing but will reflect light is
a. an element.
b. a colloid.
c. a suspension.
d. solid.
e. hydrated.
I think the answer is A</span>
The net ionic equation of the reaction is:
- Pb²⁺ (aq) +2 I⁻ (aq) → PbI2(s)
<h3>What are net ionic equations?</h3>
Net ionic equations are equations where ions which remain in solution known as spectator ions are not shown in the equation. Only ions involved in formation of product are shown.
In the given equation, sodium and nitrate ions are spectator ions.
The net ionic equation of the given reaction is as follows:
- Pb²⁺ (aq) +2 I⁻ (aq) → PbI2(s)
In conclusion, spectator ions are not shown in net ionic equation.
Learn more about net ionic equations at: brainly.com/question/19705645
#SPJ1
Answer:

Explanation:
Given the amount of heat absorbed and the amount of substance in moles, we may calculate the heat of vaporization. Heat of vaporization is defined as the amount of heat per 1 mole of substance required to evaporate that specific substance.
Based on the value of heat of vaporization, we will identify the substance. Firstly, let's calculate the heat of vaporization:

Secondly, let's use any table for heat of vaporization values for substances. We identify that the heat of vaporization of
is 18.7 kJ/mol