chem - basics, alkali and alkaline earth metals, halogens and nobles gases, electron configuration Flashcards
What is mass
Amount of matter made up of particles
What is volume
Amount of space taken up by a substance
What is matter made of
Atoms
What are physical properties
Characteristics that describe appearance
What are chemical properties
How a substance reacts with other substances
What are atoms composed of
Subatomic particles. Protons neutrons and electrons
Where are protons and neutrons located in an atom
Nucleus Center of atom
How do electrons behave in an atom
Move rapidly to form an electron cloud around the nucleus
What is the mass comparison between protons and electrons?
An electron is 1,800 times lighter than a proton.
What charge does an electron have?
Negative charge.
What is the relationship between protons and electrons?
Their charges balance to form a neutral atom.
What defines a pure substance?
Made up of identical particles.
What is an element?
A pure substance made up of one type of atom that cannot be broken down.
Define an atom.
The smallest unit of mass, consisting of a nucleus and electrons.
What is the arrangement of the periodic table?
Periods go across, groups go down, with lighter elements at the top.
How do shells change in the periodic table?
Shells increase as you go across periods.
What do elements in the same group have in common?
They have the same number of valence electrons.
Group 1 elements are called what?
Alkali metals (e.g., lithium, sodium, potassium, rubidium)
How many valence electrons do Group 1 elements have?
1
What happens when Group 1 metals react with water?
They produce hydrogen gas and an alkaline solution (metal hydroxide).
Physical properties of Group 1 metals:
Soft, higher density, lower melting and boiling points as you move down the group.
Group 1 Chemical reaction with water
Element + Water = Hydrogen Gas (H2g) and Hydrogen Oxide with complementary metal (OH) e.g.
2Li+2H 2O→2LiOH+H 2 (g)
Reaction of sodium with water:
Sodium reacts vigorously, producing sodium hydroxide and hydrogen gas.
Reaction of potassium with water:
Potassium reacts explosively, producing potassium hydroxide and hydrogen gas.
What are the elements in Group 2 (Alkaline Earth Metals)?
Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra).
How many valence electrons do alkaline earth metals have?
They have 2 valence electrons and typically form +2 ions (except beryllium).
How does reactivity change as you move down Group 2?
Reactivity increases down the group.
What are the physical properties of alkaline earth metals?
They are soft, denser than alkali metals, and their melting and boiling points decrease down the group.
How is magnesium stored, and why?
Magnesium is stored in a dry place (not oil) because it reacts with moisture.
What do alkaline earth metals form when they react with oxygen?
They form metal oxides. e.g. (Mg + 02g = Mg0)
Do Alkaline Earth metals sink or stay afloat in water
Sink, opposite of alkali metals
What are the elements in Group 17 (Halogens)?
Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At).
How many valence electrons do halogens have?
They have 7 valence electrons and can form -1 ions.
How does reactivity change as you move down Group 17?
Reactivity decreases down the group. More electrons, more stable
What are the physical states of halogens at room temperature?
Fluorine (gas, yellow), Chlorine (gas, green), Bromine (liquid, red-brown), Iodine (solid, purple vapor), Astatine (solid, black).
What do halogens form when they react with metals and hydrogen?
They form metal halides and hydrogen halides, respectively.
halogens + metal = metal halides
halogens + hydrogen gas
= hydrogen halides very exothermic
What are the elements in Group 18 (Noble Gases)?
Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).
Why are noble gases considered inert?
They have full valence shells (8 electrons, except helium which has 2), making them very stable.
How do the boiling points of noble gases change?
Boiling and melting points increase down the group due to increasing atomic size and electron density.
What are some practical uses of noble gases?
Helium (balloons), Neon (neon signs), Argon (light bulbs), Krypton (insulation), Xenon (car manufacturing), Radon (radiotherapy).
What is the atomic structure basics?
Atomic number whole number = number of protons (= electrons). Atomic mass, decimal = number of protons + neutrons. in nucleus
What is the maximum number of electrons in each electron shell?
1st shell: 2, 2nd shell: 8, 3rd shell: 8 (can hold up to 18 in transition metals).
What are catalysts?
A substance that speeds up a chemical reaction or lowers the temperature or pressure needed to start one without getting consumed
what are isotopes?
atoms with the same element and protons but different neutron amount, so atomic mass changes.
ionic charge of alkali metals, alkaline earth metals, halogens
group 1 : +1 ion
group 2 : +2 ion
group 7 : -1 ion
