extra quesitons lock in dolohawd Flashcards
From left to right, across a period, the shielding effect ______
REMAINS CONSTANT - ITS NOT ENC, ITS THE SHIELDING SHELLS - CONSTANT.
What ion will have the smallest and largest radius: CA2+ CL- K+?
CA2+, K+, CL-. ANIONS HAVE A LARGER RADIUS BECAUSE WHEN THEY GAIN ELECTRONS, THE REPULSION MAKES THE NUCLEUR FORCE BE SHARED AMONGST MORE ELECTORNS, DISTANCING THE VALENCE ELECTRONS FROM THE NUCLEUS, INCREAISNG THE ATOMIC RADIUS.
FOR CATIONS, LOSING ELECTRONS INCREASES THE AMOUNT OF NUCLEUR FORCE PER REMAINING ELECTRON DUE TO LESS REPULSION, THIS CAUSES THE VALENCE ELECTRONS TO BE PULLED CLOSER TO THE NUCLEUS, MAKING THE ATOM SMALLER, DECREASING THE ATOMIC RADIUS.
Explain the relationship between atomic structure and emission spectra.
Electrons sit in energy levels or shells around the nucleus. When they absorb energy, they jump to a higher shell, but this is unstable. As they fall back to a lower level, they release energy as photons. The colour or wavelength of the light depends on the energy difference between shells, which shows the atom’s electron configuration and produces a unique emission spectrum.
Why does zinc fill the 3d shell before the 4s?
The 3d orbitals are slightly lower in energy than the 4s — after 4s has already filled.
FOR ANY TRASITION: METAL’S SEA OF ELECTRONS - ITS THE VALENCE ELECTRONS LOST - THYE ARE IN THE ATOM AND STILL BONDED BUT JUST IN A SEA, FOR TRANSITION USE ORBITALS LIKE ZINC 4S2, 2 ELECTRONS IN SEA.
What’s an electrode and how is it usually made?
From graphite - carries electricity - conducts it graphite is good because it has a delocalised electron which conducts electricity - mobility.
Why is graphite a good conductor of electricity compared to other covalent compounds?
Graphite is a good conductor of electricity because each carbon atom forms only three bonds, leaving one delocalised electron per atom. These electrons are free to move throughout the layers, allowing electrical current to flow. Other covalent compounds lack delocalised electrons or ions, so they cannot conduct electricity.
Why are covalent compounds poor electrical conductors and metals good?
Covalent compounds are poor electrical conductors because they do not have free electrons or ions to carry charge. Metals, however, have a sea of delocalised electrons that are free to move throughout the structure, making them excellent conductors of electricity.
Why are ionic compounds solids and simple covalent compounds usually gas or liquid?
Ionic compounds are usually solids because they consist of positive and negative ions held together by strong electrostatic forces in a giant 3D lattice. These forces lock the ions in place, giving the compound a rigid, solid structure. In contrast, simple covalent compounds are often liquids or gases because they are made of neutral molecules with weak intermolecular forces between them. These weak attractions are easy to overcome, so the molecules can move freely, resulting in low melting and boiling points. Unlike metals, covalent compounds do not have delocalised electrons or metallic bonding, so they do not behave like metals.
Why are giant covalent structures such as diamond and graphite solid and simple covalent structures usually gases or liquids?
Giant covalent structures like diamond and graphite are solids because they have strong covalent bonds throughout the entire lattice, which require a large amount of energy to break. In contrast, simple covalent structures have weak intermolecular forces between molecules, so they have low melting and boiling points and are usually liquids or gases at room temperature.
Why is water a bent molecule whereas carbon dioxide is a linear molecule?
What effect does this have on the properties of water compared to carbon
dioxide? (E.g. state, melting point, solvent properties)
Water is bent because it has two lone pairs that push the hydrogen atoms down, while carbon dioxide is linear because it has no lone pairs on the central atom. This makes water polar, so it has a higher melting point, is a liquid at room temperature, and is a good solvent. CO₂ is non-polar, so it is a gas at room temperature and a poor solvent.
What’s an electron cloud?
An electron cloud is the area around the nucleus of an atom where electrons are likely to be found. It shows where electrons move, kind of like a fuzzy zone, not exact paths.
What is the mass number?
The mass number is the total number of protons and neutrons in the nucleus of an atom.
What is atomic mass?
Atomic mass is the average mass of all the isotopes of an element, measured in atomic mass units (amu).
What is atomic nomenclature?
XAZ - atomic mass and number with charge if ion
How does the quantum mechanical model of electrons work?
Electrons are arranged in increasing energy levels called shells, numbered 1–7.
Each shell holds electrons according to the formula 2n² (where n is the shell number).
Within each shell, electrons go into subshells in this order:
s, p, d, and f, which hold 2, 6, 10, and 14 electrons.
What’s a diatomic molecule?
where 2 atoms of the same element share electrons e.g. O2, N2 … - formed in mash reactions usually.
What is a polyatomic ion?
a group of atoms bonded together and form an overcharged particle.
What’s a covalent polar bond?
A polar bond forms when the electronegativities of two atoms are very different, causing the shared electrons to be pulled closer to the more electronegative atom. This creates a dipole, or partial positive and negative charges within the bond.
What’s a covalent non-polar bond?
A non-polar bond occurs between two atoms with equal or very similar electronegativities, so the electrons are shared equally and no dipole is formed.
What’s a Covalent Network Solid?
A covalent network solid is made when some elements (mainly carbon and silicon) form strong covalent bonds in a continuous lattice structure. These solids are very hard, have very high melting points, and usually do not conduct electricity
READ AND QUIZ URSELF ON METALLIC PROPERTIES.
Metals are hard, have high boiling points, and high densities because of the strong forces between closely packed particles. They conduct electricity and heat well due to the presence of free-moving electrons, which also allow them to be shiny (lustrous). Metals are malleable and ductile as the attractive forces between atoms are stronger than repulsive forces when ions move. They tend to lose electrons easily, making them reactive.
How does a mass spectroscopy work in 3 simple steps?
Vaporise the sample so it turns into gas.
Ionise the atoms or molecules and accelerate them using an electric field.
The ions then pass through a magnetic field, which separates them based on their mass — lighter ions bend more, heavier ones bend less.
How does electromagnetic spectra work?
The electromagnetic spectrum includes all types of electromagnetic radiation, from gamma rays (high energy) to radio waves (low energy), with visible light in the middle. The colour we see depends on the wavelength reflected by an object, while other wavelengths are absorbed. In absorption spectra, elements absorb specific wavelengths of light, creating dark lines in a spectrum. In emission spectra, excited atoms release energy as light at specific wavelengths, producing bright lines. These unique spectral lines help identify elements and compounds.
What’s the AES - atomic emission spectronomy?
Atomic Emission Spectroscopy (AES) detects the light emitted by electrons when they fall from excited states back to ground state. A hot flame excites electrons, and the light they release is split into a spectrum to identify elements based on their unique wavelengths.
