Block 1 Flashcards
What are the 3 ways we look at a chemical reaction
- Observe
- Particulate (Think about the reaction and what’s happening at the molecular level)
- Symbolic
As chemists how should we view a chemical reaction
We should Particulate aka think about the reaction and what’s happening at the molecular level
Who is J.J Thomsom and what did he do?
He is a British Physicist from Cambridge. His research in cathode rays led to the discovery of the electron, and he pursued further innovations in atomic structure exploration.
What are canal rays?
Also called an anode ray, they are a beam of positive ions that is created by certain types of gas-discharge tubes
What are cathode rays?
A cathode ray is a beam of electrons in a vacuum tube traveling from the negatively charged electrode (cathode) at one end to the positively charged electrode (anode). They are also called electron beams.
What are Cathode ray tubes?
The cathode-ray tube is a vacuum tube that contains one or more electron guns and a phosphorescent screen and is used to display images. It modulates, accelerates, and deflects electron beam onto the screen to create the images..
Why is the Charge to Mass ratio (e/m) important?
Knowing the charge to mass ratio allows us to calculate the mass of the electron or proton by measuring charge effects. … Since the force on a charged particle is proportional to its charge, the deflection of a beam of charged particles will be the same for all particles with the same charge to mass ratio.
True or False. Electrons are lighter and smaller than atoms?
True
What are the three most common types of radioactive emissions?
Beta (B), Alpha (a), and Gamma (y) *Letters do not exactly represent the symbol for these radioactive emissions.
What charge do alpha particles have?
They have a positive charge
What charge do Beta particles have?
They can either have a negative or a positive charge?
What charge do Gamma particles have?
They have no charge
If you were to have 3 substances: paper, 0.5cm lead, and 10cm led in a row, out of the 3 most common types of radioactive emissions which could reach the 10cm led?
Gamma rays (y)
What is a geiger counter?
A Geiger counter is an instrument used for detecting radioactive emissions, most commonly beta particles and gamma rays.
What is a scintillation counter?
A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillating material, and detecting the resultant light pulses.
What is the difference between the gieger counter and the scintillation counter?
The GM counter can detect all kinds of radiations such as alpha, beta and gamma rays, whereas the scintillation counter can detect only ionizing radiations.
What is the bohr model and is it used in modern times?
In atomic physics, the Rutherford–Bohr model or Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System. This model works easily in modern times with very simple atoms such as hydrogen although would be incorrect for other atoms these days and require another model.
What are ions?
Positively or negatively charged particles.
What is a mass spectrometer?
A mass spectrometer produces charged particles (ions) from the chemical substances that are to be analyzed. The mass spectrometer then uses electric and magnetic fields to measure the mass (“weight”) of the charged particles.
True or False Hydrogen does not have neutrons?
True.
Who discovered the neutron and in what year?
Chadwick (1932)
True or False neutron particles will have approximately the same mass as the proton of an atom.
True
How many atoms are in the human body?
7x10^27
Define atomic mass
Atomic mass is the mass of a single atom (its nuclei) of a chemical element. When calculating atomic mass the mass of electrons is negligible as its weight is too small to make a difference to our calculation.
What is the difference between the relative mass and the absolute mass?
The relative mass in the average atomic mass although the absolute mass is the exact sum of the number of protons and neutrons mass.
What is the difference between the relative charge and the absolute charge?
The relative charge in the average charge and the absolute charge is the exact sum of the charge.
What is the atomic mass number (atomic number) (A) also known as the mass number?
The total number of protons and neutrons (together known as nucleons) in an atomic nucleus.
Where would you find the atomic mass number on the periodic table for each element?
Below the element symbol.
What happens if you change the number of protons for an element?
Nothing happens to that element you are merely just changing which element you are looking at.
What happens if you change the number of neutrons for an element?
- The mass will change for that element (atom) 2. An isotope will form
What are isotopes?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties
What is the relative atomic mass?
It is the ratio of the average mass per atom of an element from a given sample
What is the definition of a mole 2020?
The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6.02214076 × 10^23 elementary entities. This number is the fixed numerical value of the Avogadro constant, NA, when expressed in mol−1, and is called the Avogadro number.
How to calculate atomic weight for multiple isotopes?
The atomic weight of multiple isotopes can be found by multiplying the abundance of an isotope of an element by the atomic mass of the element and then adding the results together. This equation can be used with elements with two or more isotopes: Example: Carbon-12: 0.9889 x 12.0000 = 11.8668. Carbon-13: 0.0111 x 13.0034 = 0.1443.
What is the avogadro constant (Na)?
Avogadro’s constant, is the number of particles found in one mole of a substance. 6.02214076 × 10^23.
How do you find the number of electrons in an atom?
This is the same as the number of protons in an atom which is the atomic number.
What are the 4 main elements in the human body?
O, C, H, and N
What percentage of the mass of a 60kg person is made up of Oxygen?
25.5%
What percentage of the mass of a 60kg person is made up of Carbon?
9.5%
What percentage of the mass of a 60kg person is made up of Hydrogen?
63%
What is Quantization?
Quantization is the concept that a physical quantity can have only certain discrete values.
How do atoms interact with the rest of the world?
Via the atom’s outer electrons
What are excited atoms?
An excited-state atom is an atom in which the total energy of the electrons can be lowered by transferring one or more electrons to different orbitals
What is spectroscopy?
Spectroscopy is a scientific measurement technique. It measures light that is emitted, absorbed, or scattered by materials and can be used to study, identify and quantify those materials.
What can the Emission and absorption of light tell us about a molecule?
It can tell us about the chemical(s) present and the amount present in a sample.
What are gas discharge tubes?
A gas discharge tube is usually a glass tube with two electrodes sealed through its walls. When a voltage is applied to the two electrodes and the pressure of the gas in the tube is reduced, eventually a pressure is reached at which a current flows, and the gas begins to glow.
What is electromagnetic radiation?
A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
What is the wavelength?
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave’s shape repeats
What is amplitude?
The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position
What is visible light?
Visible light is a form of electromagnetic (EM) radiation, as are radio waves, infrared radiation, ultraviolet radiation, X-rays and microwaves. Generally, visible light is defined as the wavelengths that are visible to most human eyes.
What is ultraviolet radiation?
Ultraviolet light is a type of electromagnetic radiation that makes black-light posters glow, and is responsible for summer tans — and sunburns. However, too much exposure to UV radiation is damaging to living tissue
What is the difference between visible light and ultraviolet radiation?
Ultraviolet (UV) light has shorter wavelengths than visible light. Though these UV waves are invisible to the human eye, some insects, like bumblebees, can see them! UV light also has more energy than visible light.
What is the speed of light?
The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is 3.00x10^8 m/s
True or False? Shorter wavelength = Higher frequency
True
What is the electromagnetic spectrum?
The range of wavelengths or frequencies over which electromagnetic radiation extends.
How do energy levels relate to the electromagnetic spectrum?
As you go further up the electromagnetic spectrum and the wavelengths become shorter energy should increase
What is the Balmer series?
The Balmer series, or Balmer lines in atomic physics, is one of a set of six named series describing the spectral line emissions of the hydrogen atom.
What is the lyman series?
The Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n = 1, the lowest energy level of the electron.
What is the difference between Lyman and Balmer series?
The key difference between Lyman and Balmer series is that Lyman series forms when an excited electron reaches the n=1 energy level whereas Balmer series forms when an excited electron reaches the n=2 energy level