This positively charged particle determines an element’s atomic number.
What is a proton?
Across a period from left to right, atomic radius generally changes in this way.
What is decreases?
A chlorine atom has this many valence electrons.
What is 7?
Name Na₂SO₄.
What is sodium sulfate?
This intermolecular force exists between every atom and molecule.
What are London dispersion forces?
Atoms of the same element that have different numbers of neutrons are called these.
What are isotopes?
Moving down a group, first ionization energy generally changes in this way.
What is decreases?
Give the Lewis structure for carbon dioxide.
What is O=C=O, with two lone pairs on each oxygen?
Write the formula for iron(III) oxide.
What is Fe₂O₃?
Water is polar even though it contains two identical O–H bonds because of this molecular feature.
What is its bent, asymmetrical shape?
Give the numbers of protons, neutrons, and electrons in an aluminum-27 ion, Al³⁺.
What are 13 protons, 14 neutrons, and 10 electrons?
A positive ion is normally smaller than its neutral atom for this reason.
What is the loss of electrons reduces repulsion and may remove an occupied energy level?
Give the Lewis structure and molecular shape of ammonia, NH₃.
What is nitrogen with three N–H single bonds and one lone pair; trigonal pyramidal?
Name N₂O₅.
What is dinitrogen pentoxide?
The strongest intermolecular force between ammonia molecules is this.
What is hydrogen bonding?
Chlorine is 75% chlorine-35 and 25% chlorine-37. Calculate its average atomic mass.
What is 35.5 u?
Of Na, Mg, and Al, this element has the largest atomic radius.
What is sodium?
A bond with an electronegativity difference of about 1.0 is classified as this type.
What is polar covalent?
Name CuSO₄·5H₂O.
What is copper(II) sulfate pentahydrate?
Carbon dioxide contains polar bonds but is a non-polar molecule for this reason.
What is its linear, symmetrical shape causes the bond dipoles to cancel?
Rutherford’s gold-foil experiment led to this conclusion about atomic structure.
What is that the atom is mostly empty space with a small, dense, positively charged nucleus?
Explain the opposite reactivity trends for Group 1 metals and Group 17 halogens as you move down a group.
What is Group 1 becomes more reactive because electrons are lost more easily, while Group 17 becomes less reactive because added electrons are less strongly attracted?
Elements in Period 3 and below can sometimes have more than eight valence electrons. This is called this.
What is an expanded octet?
Give the names of HCl(aq) and H₂SO₄(aq), in that order.
What are hydrochloric acid and sulfuric acid?
Ethanol has a much higher boiling point than methoxymethane, even though they have the same molecular formula, because ethanol can form this attraction.
What is hydrogen bonding?