Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
What are atomic radii trends along the...
i) Period, and why? ii) Family, and why? |
i) Going across a period, atomic radius decreases, because as we go along the period, another proton and electron is added to the element, resulting in a larger attraction between the two, and thus a smaller atom.
ii) Going down a family, atomic radii increase, because as we go down each step, another energy level is added, increasing the radius across the elements. |
|
|
Who created the modern day periodic chart?
|
Dmitri Mendeleev published the original scheme by increasing atomic mass, though there were some discrepancies with this arrangement. (Ar and K, Te and I) In 1914, Henry Mosely, a British physicist, arranged the elements in order of atomic number and not atomic mass.
|
|
|
In reguards to Ionic radius...
a) Are positive ions radii typically smaller or larger than the neutral atom? b) Are negative ions' radii typically smaller or larger than the neutral atom? |
a) Smaller, more attraction because of a smaller number of electrons compared to the protons.
b) Larger, more repulsion because of a larger number of electrons compared to the protons. |
|
|
What is the definition of atomic radius?
|
Half the distance between the protons in a bond between like atoms.
|
|
|
What is the Periodic Law?
|
An element is a function of its atomic number. When elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern.
|
|
|
What are the trends in Electronegativity (EN) along the...
1. Period? 2. Family? |
1. Along the period, EN increases, because as we go across the period, the atoms want less and less to lose their electrons, and more and more to gain them, as it goes across from metals to nonmetals.
2. Along the family, EN decreases because adding one more electron to a larger atom isn't going to have as much as an effect as it would on a smaller atom. |
|
|
Which groups of the periodic table are these family names?
1. The Halogen Gases 2. The Alkali Metals 3. The Noble Gases 4. The Alkaline-Earth Metals 5. Transition Metals |
1. Group 17
2. Group 1 3. Group 18 4. Group 2 5. Groups 3-12 |
|
|
Who originally measured the attraction an atom has for a shared pair of electrons (Electronegativity)?
|
Linus Pauling
|
|
|
What is ionization energy? What is 2nd ionization energy?
|
1sthe amount of energy required to remove the outermost electron from a gaseous atom. 2nd ionization energy is the energy required to remove the next electron after that.
|
|
|
Why is it that, across a period, the ionization energy of an atom increases?
|
Across the period, ionization energy increases as atomic radius decreases. The stronger attraction between the protons and neutrons in the decreased radius makes it more difficult to remove electrons.
|
|
|
Why does ionization energy decrease down a family?
|
The greater atomic radius combined with the lack of stability in the larger atom decreases the ionization energy because there is not as great an attraction between the protons and electrons. Electrons are therefore easier to remove from the atom.
|
|
|
Electron affinity is what?
|
The energy required or given off when a neutral atom gains an electron. (Opposite of ionization energy)
|
|
|
What are the trends of electron affinity going...
i) down a family? ii) across a period? |
i) Down a family, affinity decreases, because as the atoms get bigger and bigger, the addition of one electron simply won't make as much a difference as it would in a smaller atom.
ii) Across a period, the energy given off increases, because across the table, the atoms want more and more to be like a noble gas, and in order to do that, they need to lose a lot of energy. |
|
|
Among metals, does reactivity decrease or increase across the period? Down a family?
|
Reactivity decreases along a period because the atoms have more and more electrons to lose, making reactions less violent. Down a family, it increases because electrons are easier to lose, and so the reaction happens faster and more violently.
|
|
|
Among nonmetals, does reactivity decrease or increase across the period? Down a family?
|
Reactivity among nonmetals increases along the period, because the atoms need less and less electrons to be like a noble gas, so the reactions happen more violently. Down a family, reactivity decreases because of the sheer size difference. It is more difficult for a larger atom to take on more electrons, so it is not as reactive.
|
