Periodic Table of Elements - Quarter 1, Lesson 3

Questions and Answers

What is the periodic law based on?

Increasing atomic number and chemical properties (correct)

Decreasing atomic mass and physical properties

Increasing atomic mass and chemical properties

Decreasing atomic number and similar mass numbers

Which elements are part of the same grouping characterized by high reactivity?

Boron, silicon, germanium

Calcium, strontium, barium

Fluorine, chlorine, bromine

Lithium, sodium, potassium (correct)

What distinguishes isotopes of an element?

Different atomic masses and the same atomic number (correct)

Identical mass and atomic numbers

Different atomic numbers and the same mass number

Different chemical properties and atomic mass

What characteristic do all metals generally share?

High conductivity of heat and electricity Signup and view all the answers

Which two scientists are credited with the early classification of the periodic table?

Dimitri Mendeleev and Lothar Meyer Signup and view all the answers

Why did Mendeleev's periodic table stand out from Meyer's?

It predicted the existence of undiscovered elements. Signup and view all the answers

Which of the following groups demonstrates similar chemical properties?

Lithium, sodium, potassium Signup and view all the answers

What property distinguishes nonmetals from metals on the periodic table?

Brittleness and lack of luster Signup and view all the answers

Which statement accurately describes the state of non-metals at room temperature?

Most non-metals are gases. Signup and view all the answers

What property is NOT characteristic of metals?

Metals are non-ductile. Signup and view all the answers

What is the primary difference between metals and non-metals based on their physical properties?

Metals are shiny, while non-metals are usually dull. Signup and view all the answers

Which of the following statements about metalloids is TRUE?

Metalloids can conduct heat better than non-metals but worse than metals. Signup and view all the answers

How are elements organized within the periodic table's groups?

Elements in groups share similar physical or chemical properties. Signup and view all the answers

What does AMU stand for?

Atomic Mass Unit Signup and view all the answers

What is true about the mass of one proton?

It is equal to one AMU. Signup and view all the answers

How do you calculate the number of neutrons in an element?

Atomic weight - Atomic number Signup and view all the answers

Which of the following symbols represents a noble gas?

He Signup and view all the answers

What distinguishes valence electrons from other electrons?

They participate in chemical bonding. Signup and view all the answers

Which element is a liquid at room temperature?

Mercury Signup and view all the answers

In the periodic table, what state of matter do most metals belong to?

Solids Signup and view all the answers

What is the atomic number used to find?

Number of protons Signup and view all the answers

What discovery provided significant support for Mendeleev’s work?

Gallium Signup and view all the answers

What is the modern interpretation of the periodic law?

Properties of elements are periodic functions of their atomic numbers. Signup and view all the answers

What does the atomic number represent?

The unique number of protons in an atom. Signup and view all the answers

If an element has an atomic mass of 11 and 5 protons, how many neutrons does it have?

6 neutrons Signup and view all the answers

Which of the following statements is true about isotopes?

Isotopes have the same atomic number but different numbers of neutrons. Signup and view all the answers

Which element has an atomic number of 1?

Hydrogen Signup and view all the answers

How is atomic mass calculated?

By adding the number of protons and neutrons. Signup and view all the answers

Which of the following elements is organized vertically in the periodic table based on similar properties?

Sodium and Potassium Signup and view all the answers

Which group of elements is known for having a single valence electron and high reactivity?

Alkali Metals Signup and view all the answers

What is a key characteristic of alkaline earth metals?

They have two valence electrons. Signup and view all the answers

What is the rule of octet related to atomic bonding?

Atoms bond to achieve eight electrons in their outermost shell. Signup and view all the answers

Which of the following elements is hydrogen classified with?

Alkali Metals Signup and view all the answers

Why are alkali metals never found as free elements in nature?

They react violently with water. Signup and view all the answers

How many protons and electrons does a hydrogen atom have?

One proton and one electron Signup and view all the answers

What kind of elements are located in the columns labeled 3-12 on the periodic table?

Transition Metals Signup and view all the answers

What do atoms with 6, 7, or 8 valence electrons typically do during bonding?

They gain electrons. Signup and view all the answers

Study Notes

Essential Learning Competencies

Differentiate between atomic number, mass number, and isotopes.
Identify elements based on their distinguishing features.

Learning Objectives

Understand the periodic law and element organization in the periodic table.
Predict properties of elements based on their periodic table location.
Classify metals, nonmetals, and metalloids by properties and placement.

Historical Context

Early chemists grouped elements by similar behaviors; examples include:
- Li, Na, K: reactive, shiny, good conductors.
- Ca, Sr, Ba: less reactive, also shiny and conductive.
Dimitri Mendeleev (1869) and Lothar Meyer (1870) organized elements by increasing atomic mass and recognized periodic relationships.
Mendeleev predicted undiscovered elements (e.g., gallium, germanium) based on his table, gaining support for his work.

Modern Periodic Law

Modern periodic law states that element properties are periodic functions of atomic numbers, not masses.
The periodic table is arranged by increasing atomic numbers, grouping similar properties in vertical columns.

Understanding the Periodic Table

Atomic Number: Number of protons in an element; unique to each element.
Atomic Mass: Sum of protons and neutrons; represents the weight of the atom.
Isotopes: Atoms with identical protons but differing neutrons.

Chemical Symbols

Each element has a unique symbol, either a single capital letter or a combination of capital and lowercase letters.

States of Matter

Most metals (except Hg) are solids; some are softer (e.g., Li, Na) while others are harder (e.g., Cu, Fe).
Nonmetals predominantly exist as gases; exceptions include solid forms like sulfur and phosphorus.
Metalloids exhibit properties of both metals and nonmetals.

Classification of Elements

Metals:
- Good conductors of heat/electricity, shiny, ductile, and malleable.
- Reactive, especially with water.
Nonmetals:
- Poor conductors, brittle if solid, dull appearance, often gaseous.
Metalloids:
- Intermediate properties, can be shiny or dull, better conductors than nonmetals but less than metals.

Periods and Groups

Elements are arranged in:
- Horizontal Rows (Periods): No similar property correlation.
- Vertical Columns (Groups/Families): Similar properties among elements in the same column.

Specific Groups in the Periodic Table

The periodic table includes:
- Main-group elements (columns 1, 2, 13-18).
- Transition metals (columns 3-12).
- Inner transition metals (lanthanides and actinides).

Alkali Metals

Located in Group 1, characterized by:
- Shiny appearance, clay-like consistency, and softness.
- Highly reactive, especially with water; not found uncombined in nature.

Alkaline Earth Metals

Found in Group 2:
- Have two valence electrons, including magnesium and calcium.
- Also reactive, but less so than alkali metals; not found uncombined in nature.

Reactivity Concepts

Reactivity relates to incomplete valence electron levels; atoms achieve stability by completing their outer shells.
Atoms with fewer valence electrons tend to lose them; those with 6, 7, or 8 gain during bonding.

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Description

This quiz covers key concepts from the periodic table of elements, including atomic number, mass number, and isotopes. Students will explore the organization of elements and learn how to predict general properties based on their locations. It’s designed for STEM students and aligns with essential learning competencies.