Periodic Table and Historical Development

<p>They have similar chemical properties (B)</p> Signup and view all the answers

<p>The transition metals are classified as metals (A)</p> Signup and view all the answers

<p>The number of filled electron shells increases (A)</p> Signup and view all the answers

<p>Group 15 (B), Group 18 (D)</p> Signup and view all the answers

<p>The number of shells occupied increases (C)</p> Signup and view all the answers

<p>Dividing elements into groups of three with similar properties (C)</p> Signup and view all the answers

<p>John Newlands (B)</p> Signup and view all the answers

<p>Leave gaps for undiscovered elements and predict their properties (D)</p> Signup and view all the answers

<p>It was only valid for the first 17 elements (A)</p> Signup and view all the answers

<p>1870 (B)</p> Signup and view all the answers

<p>Attempted to classify substances as metals or non-metals (D)</p> Signup and view all the answers

<p>Chemical properties relate to atomic mass (C)</p> Signup and view all the answers

<p>Atoinne Lavoisier (B)</p> Signup and view all the answers

<p>+2 (B)</p> Signup and view all the answers

<p>Vanadium (V) oxide (A)</p> Signup and view all the answers

<p>Tungsten (C)</p> Signup and view all the answers

<p>Potassium (VII) manganate (B)</p> Signup and view all the answers

<p>Used in thermometers (B)</p> Signup and view all the answers

<p>Atomic size (C), Melting point (D)</p> Signup and view all the answers

<p>They have a full valence shell of electrons. (B)</p> Signup and view all the answers

<p>They decrease because the atomic size increases. (C)</p> Signup and view all the answers

<p>Neon (B)</p> Signup and view all the answers

<p>Gray with shiny surfaces and soft. (C)</p> Signup and view all the answers

<p>The mass of the atoms increases. (D)</p> Signup and view all the answers

<p>Reactivity increases. (B)</p> Signup and view all the answers

<p>Flash bulbs and lasers. (D)</p> Signup and view all the answers

<p>They become weaker. (C)</p> Signup and view all the answers

<p>Produces an alkaline metal hydroxide and hydrogen gas. (C)</p> Signup and view all the answers

<p>Keep them in paraffin oil. (C)</p> Signup and view all the answers

<p>They have 7 valence electrons. (C)</p> Signup and view all the answers

<p>Melting point. (A)</p> Signup and view all the answers

<p>It becomes darker. (D)</p> Signup and view all the answers

<p>They consist of covalent molecules. (C)</p> Signup and view all the answers

<p>They are all diatomic molecules. (C)</p> Signup and view all the answers

<p>Reactivity decreases down the group (D)</p> Signup and view all the answers

<p>They are good conductors of electricity and heat (D)</p> Signup and view all the answers

<p>Amphoteric (B)</p> Signup and view all the answers

<p>Manganese (D)</p> Signup and view all the answers

<p>It increases (B)</p> Signup and view all the answers

<p>Sulfur (C)</p> Signup and view all the answers

<p>Blue (B)</p> Signup and view all the answers

<p>Decreases (D)</p> Signup and view all the answers

<p>Chromium (C)</p> Signup and view all the answers

<p>The number of electrons increases across a period (B)</p> Signup and view all the answers

<p>CrCl3 (C)</p> Signup and view all the answers

<p>8 (B)</p> Signup and view all the answers

<p>To make filament bulbs (C)</p> Signup and view all the answers

<p>5 (A)</p> Signup and view all the answers

<p>Sodium (B)</p> Signup and view all the answers

<p>Nickel (Ni) (D)</p> Signup and view all the answers

<p>Iron (Fe) (A)</p> Signup and view all the answers

<p>16 (A)</p> Signup and view all the answers

<p>The number of shells equals the period number. (B)</p> Signup and view all the answers

<p>+7 (A)</p> Signup and view all the answers

<p>Oxygen (A)</p> Signup and view all the answers

<p>14 (D)</p> Signup and view all the answers

<p>Helium (A)</p> Signup and view all the answers

<p>Increasing proton number (A)</p> Signup and view all the answers

<p>32 elements (D)</p> Signup and view all the answers

<p>Groups (D)</p> Signup and view all the answers

<p>Highly reactive with water (D)</p> Signup and view all the answers

<p>Increases (C)</p> Signup and view all the answers

<p>Presence of metals only (D)</p> Signup and view all the answers

<p>Decreases (A)</p> Signup and view all the answers

<p>18 elements (C)</p> Signup and view all the answers

<p>He grouped elements in sets of three with similar properties. (A)</p> Signup and view all the answers

<p>Lothar Meyer (D)</p> Signup and view all the answers

<p>He had to leave gaps for undiscovered elements. (D)</p> Signup and view all the answers

<p>He proposed the Law of Octaves based on properties of elements. (A)</p> Signup and view all the answers

<p>He included light and heat as elements. (D)</p> Signup and view all the answers

<p>Element properties and atomic mass correlated. (C)</p> Signup and view all the answers

<p>Patterns continued indefinitely across all elements. (B)</p> Signup and view all the answers

<p>He rearranged elements by increasing atomic number. (D)</p> Signup and view all the answers

<p>It increases because the number of electron shells increases. (B)</p> Signup and view all the answers

<p>They increase due to stronger intermolecular forces. (B)</p> Signup and view all the answers

<p>They produce alkaline solutions and hydrogen gas. (D)</p> Signup and view all the answers

<p>Due to covalent molecular structure and weak intermolecular forces. (A)</p> Signup and view all the answers

<p>They readily react with water to form hydroxides. (C)</p> Signup and view all the answers

<p>Fluorine (B)</p> Signup and view all the answers

<p>Use forceps to handle them. (A)</p> Signup and view all the answers

<p>Increase in atomic size leading to heavier atoms. (B)</p> Signup and view all the answers

<p>Reactivity decreases down the group (A)</p> Signup and view all the answers

<p>They conduct electricity and heat (A)</p> Signup and view all the answers

<p>Electronegativity increases (D)</p> Signup and view all the answers

<p>Fe2+ (A)</p> Signup and view all the answers

<p>It is amphoteric (C)</p> Signup and view all the answers

<p>Manganese (B)</p> Signup and view all the answers

<p>2.8.1 (D)</p> Signup and view all the answers

<p>Metallic properties decrease (D)</p> Signup and view all the answers

<p>Most transition elements have multiple oxidation states (A)</p> Signup and view all the answers

<p>Colored compounds (C)</p> Signup and view all the answers

A grouping of three elements with similar chemical properties, where the middle element's atomic mass is roughly the average of the other two.

The observation that elements with similar properties reappear every eighth element when arranged by increasing atomic mass. It helped show a periodic pattern but was limited to the first 17 elements.

The principle that the chemical properties of elements are periodic functions of their atomic masses. Elements with similar characteristics are arranged in groups, and he left gaps for yet-to-be discovered elements.

The average mass of an atom of an element, measured in atomic mass units (amu).

The characteristics of a substance related to how it interacts with other substances during chemical reactions.

Vertical columns in the periodic table containing elements with similar chemical properties due to the same number of valence electrons.

Horizontal rows in the periodic table, with elements in the same period having the same number of electron shells.

The way electrons are organized in energy levels and sublevels around an atom's nucleus. This arrangement determines an element's chemical behavior.

Moseley discovered that the number of protons in an atom (atomic number) determines its chemical properties, not its atomic mass. This led to the arrangement of elements in the periodic table by increasing atomic number.

The number of valence electrons in the outermost shell of an atom determines the group it belongs to. Elements in the same group have the same number of valence electrons.

There are 7 periods in the periodic table, each representing a different number of occupied electron shells in an atom.

The position of an element in the periodic table (group and period) can be determined by its atomic number, which reveals the number of protons and electrons.

The number of valence electrons (outermost shell electrons) directly corresponds to the group number of an element. For example, Group 1 elements have 1 valence electron, Group 2 elements have 2, and so on.

As you move down a group in the periodic table, the number of filled electron shells increases. This means atoms get larger going down a group.

Elements in Group 1 of the periodic table (Li, Na, K, Rb, Cs, Fr). They are highly reactive metals, readily forming hydroxides and releasing hydrogen gas when reacting with water.

Elements in Group 17 of the periodic table (F, Cl, Br, I, At). They are highly reactive non-metals that exist as diatomic molecules.

Molecules composed of two atoms of the same element, like F2, Cl2, Br2, I2, and At2.

Weak forces of attraction between molecules.

The size of an atom, usually measured as the radius of its electron cloud.

The temperature at which a substance changes from a solid to a liquid.

Electrons in the outermost shell of an atom, involved in chemical bonding.

Noble gases are unreactive, don't conduct heat or electricity well, and exist as colorless gases at room temperature.

Noble gases are unreactive because their electron arrangement is stable, meaning they don't need to gain or lose electrons to become stable.

Alkali metals are soft, shiny, good conductors of heat and electricity, and have relatively low melting points.

Alkali metals have a larger atomic size and lower melting/boiling points as you go down the group.

Alkali metals are highly reactive, increasing in reactivity as you go down the group.

Noble gases are unreactive due to their full outer shell of electrons, while alkali metals are highly reactive due to their single valence electron.

Noble gases have various uses, from filling balloons to lighting advertising boards.

Alkali metals are used in various applications, but their reactivity requires careful handling.

A transition metal element used to speed up a specific chemical reaction without being consumed in the process.

A process using iron as a catalyst to produce ammonia from nitrogen and hydrogen gases.

A process using vanadium oxide to produce sulfuric acid from sulfur dioxide and oxygen.

A process using platinum to produce nitric acid from ammonia and oxygen.

A process using nickel to add hydrogen to unsaturated fats, turning them into margarine.

Halogens become less reactive as you move down Group 17 (from fluorine to astatine).

Halogens react with water to form two acids: a hydrohalic acid (HX) and a hypohalous acid (HOX).

The first three periods in the periodic table (periods 1, 2, and 3) are called short periods.

Periods 4, 5, 6, and 7 are called long periods because they contain many more elements than the short periods.

As you move across Period 3 from sodium to chlorine, the atomic size decreases, electronegativity increases, and metallic properties decrease.

The tendency of an element to lose electrons and form a positive ion.

The tendency of an element to attract electrons and form a negative ion.

Elements in Groups 3 - 12 of the periodic table, known for their shiny, ductile, malleable, and conductive properties.

Many transition metal ions produce coloured compounds and solutions.

The number of valence electrons in the outermost shell determines the group an element belongs to. Elements in the same group share the same number of valence electrons.

The number of electron shells in an atom corresponds to the period it resides in. So, elements within a period have the same number of electron shells.

There is a pattern to the maximum number of electrons each shell can hold. The first shell holds 2, the second shell holds 8, and subsequent shells have increasing maximums.

Valence electrons are the electrons in the outermost shell of an atom, and they are the ones involved in forming chemical bonds.

Alkali metals belong to Group 1 (except hydrogen) of the periodic table, and they're highly reactive metals that readily form hydroxides when interacting with water.

Halogens are located in Group 17 of the periodic table and are very reactive nonmetals. They exist as diatomic molecules, meaning they pair up with another atom of the same element.

Transition metals are found in Groups 3-12 of the periodic table. They are known for their shiny, durable, and conductive properties, and they are used in various applications.

Halogens react with water to form two acids: a hydrohalic acid (HX) and a hypohalous acid (HOX). For example, chlorine (Cl) reacts with water to form hydrochloric acid (HCl) and hypochlorous acid (HOCl).

The periodic table has 7 periods. The first three periods (1, 2, and 3) are called short periods because they contain fewer elements. Periods 4, 5, 6, and 7 are called long periods because they contain many more elements.

Moving across Period 3 from Sodium (Na) to Chlorine (Cl), atomic size decreases, electronegativity increases, and metallic properties decrease. This means Sodium is big, not electronegative, and metallic, while Chlorine is small, electronegative, and non-metallic.

Electropositivity refers to the tendency of an element to lose electrons and form a positive ion. Elements with high electropositivity easily give away electrons.

Electronegativity is the tendency of an element to attract electrons and form a negative ion. The higher the electronegativity, the stronger its pull on electrons.

Many transition metal ions form compounds and solutions that are colored. This vibrant color arises from the way electrons absorb and emit light within the metal's d orbitals.

Many precious gemstones get their beautiful colours from the presence of transition metal ions within their structures. For example, emerald is green because of nickel and iron ions.

Transition metals can form complex ions, which are molecules of metal surrounded by other atoms or molecules called ligands. These complex ions often have unique colors and properties.

Alkali metals readily react with water to produce a metal hydroxide solution and hydrogen gas. They also react with oxygen to form metal oxides.

Halogens (Group 17) are nonmetals that exist as diatomic molecules (e.g., F2, Cl2) and have 7 valence electrons.

Halogen reactivity decreases as you move down the group (from fluorine to astatine).

Atomic size increases as you move down a group in the periodic table.

Melting and boiling points increase down a group in the periodic table because the attraction between atoms gets stronger.

Alkali metals are highly reactive, so they must be handled with caution: stored in oil, use forceps, wear goggles and gloves.

Elements are organized in the periodic table based on their properties. As you move across a period or down a group, various properties change predictably.