Chemistry test 2

Reactivity of the Halogens

Decreases as you go down the group.

Melting and Boiling Points of Halogens

Increase as you go down the group.

Diatomic Molecules

Molecules formed by two atoms; halogens exist as F2, Cl2, etc.

Halide Ions

Ions formed by halogens with a charge of -1.

Reactivity of Alkali Metals

Increases as you go down Group 1.

Metal water

Produced when alkali metals react with water, e.g., sodium hydroxide + hydrogen.

Transition Metals vs. Group 1 Metals

Transition metals have higher melting points, higher densities, greater strength, and greater hardness.

Outer Shell Electrons in Halogens

All halogens have 7 electrons in their outer shell.

Attraction and Reactivity in Elements

Reactivity is determined by how easily an element can gain or lose its outer electrons.

Group 7 Color Change

The color of halogens gets darker as you move down the group.

Diatomic Nature of Halogens

Halogens share electrons in a single covalent bond between two atoms.

Properties of Transition Elements

They conduct electricity, are shiny, and typically have greater hardness and higher melting points compared to alkali metals.

Properties of Halogens

Halogens are typically diatomic, colored gases or solids at room temperature, have high electronegativity, and are highly reactive, especially with alkali metals. They possess distinct colors that deepen down the group in the periodic table.

Properties of Alkali Metals

Alkali metals are shiny, soft, and highly reactive metals that have one electron in their outer shell. They react vigorously with water to form hydroxides and can ignite spontaneously in air.

Physical Properties of Non-Metals

Non-metals are typically brittle, dull in appearance, and poor conductors of heat and electricity. They can exist in solid, liquid, or gaseous states at room temperature.

Why did it take so long for noble gases to be discovered?

Noble gases were not discovered until the late 19th century because they are colorless, odorless, and chemically inert, making them difficult to detect and study. Their lack of reactivity with other elements contributed to their elusive nature.

Why is it unlikely for neon to form a compound with iodine?

Neon is a noble gas with a full outer shell of electrons, making it chemically inert and unlikely to react with other elements, including iodine.

Why do boiling and melting points increase down the group of halogens?

Boiling and melting points increase down the group due to increased van der Waals forces as the molecules become larger and heavier.

Lithium reaction with water produces:

bubbling, moving, melts over time, and produces a red flame.

Sodium reaction with water produces:

moves faster, disappears quickly, produces hydrogen gas, smokes, bubbles, produces a orange flame

Potassium reaction with water produces:

moves even faster, smokes, releases hydrogen gas, creates sparks, popping, disappears even faster, and produces a lilac flame.

How do the Alkali metals look like and freshly cut

Li: grey solid - shiny white (oxidizes and turns white)

Na: white solid - white

K: White-grey solid - blue