In the nucleus there are two main subatomic particles: The protons and the neutrons. The number of protons in the nucleus determines the element the atom is: 1 proton = hydrogen , 99 protons = Einsteinium , 6 protons = carbon etc.
The number of neutrons in the nucleus varies from atom to atom, even atoms of the same element. This causes the mass of the nucleus to vary slightly and can effect properties such as stability or type of nuclear decay. Atoms of the same element with different masses are called isotopes. They differ by the number of neutrons with the proton in te nucleus:
1 proton + 0 neutrons = 1 particle in the nucleus = hydrogen
1 proton + 1 neutron = 2 particles in the nucleus = deuterium
1 proton + 2 neutrons = 3 particles in the nucleus = tritium
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CaSO4 - to find the molar mass, you add the element's mass number.
40.08 + 32.06 + (16x4)
= 136.14
Answer:
NaOH is the limiting reactant.
Explanation:
Hello there!
In this case, since the reaction taking place between sodium hydroxide and chlorine has is:
Which must be balanced according to the law of conservation of mass:
Whereas there is a 2:1 mole ratio of NaOH to Cl2, which means that the moles of the former that are consumed by 0.85 moles of the latter are:
Therefore, since we just have 1.23 moles out of 1.70 moles of NaOH, we infer this is the limiting reactant.
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A 4
B 6
C Be
D 10
E 22
F Ne
Explanation:
From the given table, we can simply complete the given table by identifying the meaning of each column header.
- Number of protons in an atom is the number of positively charged particles in the nucleus of the atom. Protons are positively charged particles in an atom.
- The number of neutrons are the number of neutrally charged particles occupying the nucleus of an atom.
- Atomic number is another term for the number of protons in an atom.
- Mass number is the sum of protons and neutron in an atom.
- The symbol of an element is used represent a particular atom.
Mass number = number of protons + number of neutrons
Atomic number = number of protons = number of electrons in atoms.
learn more:
Mass number brainly.com/question/2597088
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Answer:
E = 1.8 x 10⁵ J/mol
Explanation:
We are being asked the enery per mol for an emission line corresponding to 649 nm.
The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,
E = hν
We also know that the frequency is given by
ν = c/λ
where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by
E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m
E = 3.1 x 10 ⁻¹⁹ J/ photon
(Note the wavelength has to be in nanometers (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.
E = 3.1 x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol
E = 1.8 x 10⁵ J/mol