Answer:
<em>Protons:
</em>
- Positively charged particle
- The number of these is the atomic number
- All atoms of a given element have the same number of these
<em>Neutrons: </em>
- Isotopes of a given element differ in the number of these
- The mass number is the number of these added to the number of protons
Explanation:
Protons (<em>positively charged</em>), neutrons (<em>neutral</em>) and electrons (negatively charged) are smaller than an atom and they are the main subatomic particles. The nucleus of an atom is composed of protons and neutrons, and the electrons are in the periphery at unknown pathways.
The <em>Atomic number</em> (Z) indicates the number of protons (
) in the nucleus. Every atom of an element have the <em>same atomic number</em>, thus the <em>same number of protons</em>.
The <em>mass number </em>(A) is the sum of the <em>number of protons</em> () <em>and neutrons</em> (N) that are present in the nucleus: <em>A= Z + N</em>
<em>Isotopes</em> are atoms of the <em>same element </em>which nucleus have the <em>same atomic number</em> (Z), and <em>different mass number (A)</em>, it means the <em>same number of protons</em> () and a <em>different number of neutrons</em> (N). For example, the oxygen in its natural state is a mixture of isotopes:
99.8% atoms with A= 16, Z=8, and N=8
0.037% atoms with A=17, Z=8, and N=9
0.204% atoms with A=18, Z=8, and N=10
Answer:
The amount of work done on the system is 18234 J and the final positive sign means that this work corresponds to an increase in internal energy of the gas.
Explanation:
Thermodynamic work is called the transfer of energy between the system and the environment by methods that do not depend on the difference in temperatures between the two. When a system is compressed or expanded, a thermodynamic work is produced which is called pressure-volume work (p - v).
The pressure-volume work done by a system that compresses or expands at constant pressure is given by the expression:
W system= -p*∆V
Where:
- W system: Work exchanged by the system with the environment. Its unit of measure in the International System is the joule (J)
- p: Pressure. Its unit of measurement in the International System is the pascal (Pa)
- ∆V: Volume variation (∆V = Vf - Vi). Its unit of measurement in the International System is cubic meter (m³)
In this case:
- p= 10 atm= 1.013*10⁶ Pa (being 1 atm= 101325 Pa)
- ΔV= 2 L- 20 L= -18 L= -0.018 m³ (being 1 L=0.001 m³)
Replacing:
W system= -1.013*10⁶ Pa* (-0.018 m³)
Solving:
W system= 18234 J
<u><em>The amount of work done on the system is 18234 J and the final positive sign means that this work corresponds to an increase in internal energy of the gas.</em></u>
Name Arsenic
Atomic Mass 74.9216 atomic mass units
Number of Protons 33
Number of Neutrons 42
Number of Electrons 33
87) A
88) D
89) B
90) E
91) C
