Physical Science Chapter 17

Dmitri Mendeleyev is considered the father of the Periodic Table of elements because he was the first to organize the elements in a systematic way based on their atomic weights and properties. He published his version of the Periodic Table in 1869, which became the foundation for the modern Periodic Table that we use today. Mendeleyev's work was groundbreaking and laid the groundwork for our understanding of the elements and their relationships to one another.

Scandium, a missing element, was discovered to fit in between calcium and titanium in the Periodic Table according to oxidation levels. This suggests that scandium has properties and characteristics that are similar to both calcium and titanium, making it a suitable element to be placed in between them.

Each metallic element in Column 1A has the highest atomic volume and the lowest ionization energy of any element in its row. This means that these elements have the largest atomic size and are the easiest to remove electrons from. The high atomic volume is due to the presence of an extra electron shell, which increases the size of the atom. The low ionization energy indicates that these elements have a low attraction for their outermost electrons, making it easier to remove them.

An element refers to a type of matter that consists of only one type of atom. Each element on the periodic table is unique and has its own specific properties. It cannot be broken down into simpler substances by ordinary chemical means. Examples of elements include hydrogen, oxygen, carbon, and gold.

The given statement describes a compound, which is formed when two or more atoms combine in fixed ratios. A compound is a substance composed of two or more different elements chemically bonded together. In a compound, the atoms are held together by chemical bonds, which can be ionic or covalent. The fixed ratios in which the atoms combine determine the chemical formula of the compound. Examples of compounds include water (H2O), carbon dioxide (CO2), and sodium chloride (NaCl).

The elements that occur in the same row of the Periodic Table are called periods. In each period, the elements have the same number of electron shells. The period number indicates the number of shells an element's atoms have. For example, elements in the first period have one shell, elements in the second period have two shells, and so on. The elements within a period may have different properties, but they all share the common characteristic of having the same number of electron shells.

Metals are good electrical and thermal conductors, meaning they allow the flow of electricity and heat easily. They can also be hammered into thin sheets or drawn into fine wires, indicating their malleability and ductility. These properties are characteristic of metals, making them the correct answer to the question.

Elements that have similar chemical properties are not categorized into periods. Instead, elements with similar properties are grouped together in columns known as groups or families on the periodic table. Periods, on the other hand, represent the horizontal rows on the periodic table and indicate the number of electron shells an element has.

The element with the symbol Br is bromine, which is in Group 17 of the periodic table. Elements in this group, also known as the halogens, have seven valence electrons. Therefore, bromine has seven valence electrons, not five.

The given answer, "Physical property," is correct because the properties mentioned, such as melting or boiling temperature, density, and color, are all characteristics that can be observed or measured without changing the chemical composition of the substance. These properties are inherent to the substance and can help identify or classify it.

Carbon, silicon, and lead belong to the same family because they all belong to Group 14 of the periodic table. Group 14 elements are known as the carbon family and they share similar chemical properties. They all have four valence electrons and can form covalent bonds with other elements. Carbon is a nonmetal, silicon is a metalloid, and lead is a metal, but they still share similarities in terms of their chemical behavior. Therefore, it is true that carbon, silicon, and lead belong to the same family.

Metals and non-metals are two distinct categories of elements. Metals are typically solid, shiny, and good conductors of heat and electricity. They are malleable and ductile, meaning they can be hammered into thin sheets and drawn into wires. Non-metals, on the other hand, can exist in various states (solid, liquid, or gas) and are generally poor conductors of heat and electricity. They are brittle and lack the malleability and ductility of metals. This division into metals and non-metals is based on the physical and chemical properties exhibited by different elements.

Elements with atomic numbers heavier than 92 (uranium) are all man-made elements. This is because these elements are not found naturally on Earth and can only be created in a laboratory through nuclear reactions. These elements are usually produced by bombarding lighter elements with high-energy particles. Examples of man-made elements include plutonium, americium, and curium.

The correct order of increasing density for the elements Fe, Rh, and Pt is Fe, Rh, Pt. This is because density is defined as mass per unit volume, and as the atomic volume is approximately the same for all three elements, the element with the highest mass will have the highest density. Therefore, Fe, which has the lowest atomic mass among the three, will have the lowest density. Rh has a higher atomic mass than Fe but lower than Pt, so it will have a higher density than Fe but lower than Pt. Finally, Pt, with the highest atomic mass among the three, will have the highest density.

Chemistry is the correct answer because it is the scientific study of matter and the changes it can undergo to form new substances. It involves understanding the composition, properties, and behavior of matter, as well as the interactions between different substances. Chemistry plays a crucial role in various fields such as medicine, materials science, environmental science, and many others.

Chemical properties are characteristics of a substance that describe how it reacts or interacts with other substances. These properties can only be observed during a chemical reaction or a change in the substance's composition. In the context of reactivity, chemical properties determine how a material will react with other substances, such as acids, bases, or oxygen. These properties are important in understanding the behavior of materials in various chemical processes and reactions.

Valence electrons are the electrons that are found in the outermost shell of an atom, which is usually not completely filled. These electrons are involved in chemical bonding and determine the reactivity and properties of an element.

Different substances can contain the same elements but in different proportions. This means that the elements are present in varying amounts or ratios within each substance. For example, water and hydrogen peroxide both contain hydrogen and oxygen, but in different proportions. Water has two hydrogen atoms for every one oxygen atom, while hydrogen peroxide has two hydrogen atoms for every two oxygen atoms. Therefore, the correct answer is "proportions".

Non-metals are elements that do not conduct electricity. Unlike metals, non-metals have high ionization energies and electronegativities, which means they tend to gain electrons rather than lose them. This results in the formation of stable, non-conductive compounds. Additionally, non-metals have a high electron affinity, meaning they have a strong attraction for electrons, further contributing to their inability to conduct electricity. Examples of non-metals include elements such as carbon, nitrogen, oxygen, and sulfur.

The correct answer is "Family". The elements in the periodic table that are placed in the same column are called a family. These elements have similar chemical properties because they have the same number of valence electrons, which determines how they interact with other elements. The elements in a family often have similar reactivity, atomic size, and electronegativity. This grouping allows scientists to predict the behavior and properties of elements based on their position in the periodic table.

The atomic volume refers to the amount of space occupied by an atom. As we move across a period in the periodic table from left to right, atomic volume generally decreases due to the increasing number of protons and electrons, resulting in a stronger attraction between the nucleus and electrons. Therefore, oxygen (O) would have the smallest atomic volume among the given elements. Moving to the next element, nitrogen (N), it would have a slightly larger atomic volume than oxygen. Finally, phosphorus (P) would have the largest atomic volume among the three elements, as it is located further down the periodic table, indicating a larger atomic size.

Lithium has the lowest ionization energy among the given atoms. Ionization energy is the energy required to remove an electron from an atom. As we move from left to right across a period in the periodic table, ionization energy generally increases due to the increasing nuclear charge. However, lithium is an exception because it has a larger atomic radius and a lower effective nuclear charge compared to the other atoms in the list. This makes it easier to remove an electron from a lithium atom, resulting in a lower ionization energy.

The statement "Ne, Ar, and Kr are chemically active solids" is false. Ne, Ar, and Kr are noble gases, which are known for their low reactivity and stability. They exist as gases at room temperature and do not readily react with other elements to form compounds. Therefore, they are not chemically active solids.