Atomic Theory & Periodic Table Assessment Pd8

The charge of a proton is positive. Protons are subatomic particles found in the nucleus of an atom and they carry a positive electrical charge. This charge is equal in magnitude but opposite in sign to the charge of an electron, which is negative. The positive charge of protons is essential for maintaining the stability and structure of atoms, as it attracts the negatively charged electrons and keeps them in orbit around the nucleus.

The charge of an electron is negative because electrons are negatively charged particles that orbit the nucleus of an atom. This negative charge is equal in magnitude to the positive charge of a proton, which is balanced in a neutral atom.

Neutrons are electrically neutral particles, meaning they have no charge. Unlike protons, which have a positive charge, and electrons, which have a negative charge, neutrons do not possess any charge. This characteristic allows them to interact with other particles in unique ways, such as being able to penetrate atomic nuclei without being repelled by electromagnetic forces.

The atomic number of an element represents the number of protons in the nucleus of an atom. Since the atomic number of calcium is 20, this means that there are 20 protons in one atom of calcium. The atomic mass of an element represents the sum of the protons and neutrons in the nucleus. Since the atomic mass of calcium is 40, and we know that there are 20 protons, we can subtract 20 from 40 to find the number of neutrons. Therefore, there are 20 neutrons in one atom of calcium.

Valence electrons are found in the outer level of electrons. These are the electrons that are located in the highest energy level or shell of an atom. Valence electrons are important because they determine the chemical properties and reactivity of an element. The number of valence electrons influences how an atom will bond with other atoms to form compounds.

Protons are positively charged subatomic particles that are found in the nucleus of an atom. The nucleus is the central part of an atom that contains protons and neutrons. The electron cloud, on the other hand, surrounds the nucleus and contains negatively charged electrons. While protons are present in the nucleus, the electron cloud contains electrons. Therefore, the correct answer is Nucleus.

Nitrogen is not a solid. It is a gas at room temperature and pressure. Calcium, phosphorus, and potassium are all solid elements.

Neutrons are found in the nucleus of an atom. The nucleus is the central part of an atom that contains protons and neutrons. The electrons, on the other hand, are found in the electron cloud or electron energy levels surrounding the nucleus. Therefore, the correct answer is the nucleus.

The number of protons in an atom of an element can be identified from the atomic number. The atomic number represents the number of protons in an atom, which is a unique characteristic of each element. Therefore, by knowing the atomic number of an element, one can determine the number of protons present in its atom.

Group 18 elements in the periodic table are known as Noble Gases. This group includes helium, neon, argon, krypton, xenon, and radon. Noble gases are characterized by their low reactivity and full outer electron shells, making them stable and non-reactive. They are commonly used in various applications such as lighting, lasers, and cryogenics.

The atomic number of an element tells you the number of protons and electrons. Protons have a positive charge and are found in the nucleus of an atom, while electrons have a negative charge and orbit around the nucleus. The atomic number represents the number of protons in an atom, and since atoms are electrically neutral, it also represents the number of electrons. Therefore, the correct answer is "Protons & Electrons."

Most of the elements on the periodic table are metals. This is because metals make up the majority of the elements found on the left side of the periodic table. Metals are characterized by their shiny appearance, ability to conduct heat and electricity, malleability, and ductility. They are also generally solid at room temperature, with the exception of mercury. Nonmetals, metalloids, and noble gases make up a smaller portion of the periodic table.

The element represented in the diagram is Oxygen. This can be determined by looking at the chemical symbol "O" written next to the element in the periodic table. The other options, Strontium, Barium, and Sulfur, are not represented in the diagram and therefore are not the correct answer.

Group 1 elements in the periodic table are known as alkali metals because they have similar chemical properties to the element sodium hydroxide (NaOH), which is an alkali. Alkali metals are highly reactive, have low melting and boiling points, and are good conductors of electricity. They include elements like lithium, sodium, potassium, and rubidium. These metals are found in nature in compounds rather than in their pure form due to their high reactivity.

Group 17 in the periodic table is known as the Halogens. The elements in this group include fluorine, chlorine, bromine, iodine, and astatine. These elements are highly reactive and tend to form compounds with other elements, especially alkali metals. They have seven valence electrons and are known for their ability to gain one electron to achieve a stable electron configuration. Halogens are commonly used in disinfectants, bleaches, and as a source of iodine.

The number of electrons in an atom of an element can be identified from the Atomic Number. The Atomic Number represents the number of protons in the nucleus of an atom, and since atoms are electrically neutral, it also represents the number of electrons in the atom. Therefore, the Atomic Number is directly related to the number of electrons in an atom.

Group 2 elements in the periodic table are known as alkaline earth metals. These elements include beryllium, magnesium, calcium, strontium, barium, and radium. They are called alkaline earth metals because they have similar properties to the elements in Group 1 (alkali metals), but are less reactive. Alkaline earth metals have two valence electrons and readily lose them to form positive ions with a +2 charge. They are shiny, silvery-white metals that are relatively soft and have low melting points. They are also good conductors of electricity and have high thermal conductivity.

The vertical columns on the periodic table are called groups. Groups are a way of categorizing elements based on their similar chemical properties and shared electron configurations. Each group contains elements with the same number of valence electrons, which determines their reactivity and bonding behavior. The periodic table is organized into 18 groups, and elements within the same group tend to exhibit similar chemical behaviors and trends in properties.

The given question states that "Since He has an atomic number of 2, it is known as a ______." This implies that the element being referred to has an atomic number of 2. The element with atomic number 2 is helium (He), which belongs to the noble gases group on the periodic table. Therefore, the correct answer is Noble Gases.

Electrons are found in the electron cloud, which is the region surrounding the nucleus of an atom. The electron cloud is made up of different energy levels or orbitals where electrons can be found. These electrons move rapidly within the cloud, creating a probability distribution of their positions. The electron cloud is responsible for the chemical behavior of atoms, as it determines how electrons interact with other atoms to form bonds.

Copper is not brittle. It is known for its malleability, ductility, and excellent conductivity of heat and electricity. Brittle materials are prone to breaking or shattering when subjected to stress, whereas copper can be easily shaped and stretched without breaking.

Group 3-12 is known as the Transition Metals because these elements are located in the middle of the periodic table and have properties that are a transition between the highly reactive metals on the left side and the less reactive metals on the right side. They are characterized by their ability to form multiple oxidation states and their tendency to form colored compounds.

Bohr's atomic model introduced the concept of energy levels, which are specific orbits or shells where electrons can exist around the nucleus. These energy levels determine the amount of energy an electron possesses and its distance from the nucleus. This model revolutionized our understanding of electron behavior and provided a more accurate description of atomic structure. Therefore, the correct answer is "Energy Levels."

Period 3 on the periodic table consists of elements from sodium (Na) to argon (Ar). There are a total of 8 elements in Period 3, which are sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), chlorine (Cl), and argon (Ar). Therefore, the correct answer is 8.

The element mentioned in the question belongs to the Noble Gases group/family. Noble Gases are characterized by their stable and unreactive nature due to having a full valence electron shell. They are located in Group 18 of the periodic table and include elements such as helium, neon, argon, krypton, xenon, and radon. These gases are known for their low boiling points and are often used in lighting, lasers, and other specialized applications.

To determine the atomic mass of an atom, you need to know the number of protons and the number of neutrons. The atomic mass is calculated by adding the mass of the protons and the mass of the neutrons in the atom's nucleus. The number of protons determines the element's atomic number, while the number of neutrons can vary, resulting in different isotopes of the same element with different atomic masses.

The majority of elements on the periodic table exist in the solid state at room temperature and pressure. This is because the forces of attraction between the atoms or molecules in a solid are strong enough to maintain a fixed shape and volume. While there are a few elements that are liquid or gaseous at room temperature, such as mercury and hydrogen, the solid state is the most common state of matter for elements.

The correct answer is "Rounded Atomic Mass - Atomic Number". This is because the rounded atomic mass represents the total number of protons and neutrons in the atom, while the atomic number represents the number of protons. By subtracting the atomic number from the rounded atomic mass, we can determine the number of neutrons in the atom.

Ductile is the correct answer because if an element can be drawn into thin wire, it means that it can be easily stretched and shaped without breaking. This property is known as ductility. Weak refers to lack of strength, malleable refers to the ability to be hammered or pressed into shape, and flexible refers to the ability to bend easily without breaking. None of these terms specifically describe the property of being able to be drawn into thin wire.

Bromine is a nonmetal and a liquid at room temperature. It is the only element among the given options that fits this description. Mercury is a liquid, but it is a metal. Gallium is a metal, but it is a solid at room temperature. Hydrogen is a nonmetal, but it is a gas at room temperature. Therefore, the correct answer is Bromine.

The given element belongs to period 1 because the periodic table is divided into periods, which represent the number of electron shells or energy levels in an atom. The element in question must have only one electron shell, placing it in period 1.

Selenium has an atomic number of 34, which means it has 34 electrons. The electron configuration of selenium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4. The outermost orbital of selenium is the 4th energy level, specifically the 4p orbital. In the 4p orbital, there are 6 electrons present.

Alkali Metals and Halogens are similar because they both are chemically active. Both groups readily react with other elements to form compounds due to their high reactivity. Alkali metals are highly reactive because they have one valence electron that they easily lose, while halogens are highly reactive because they have seven valence electrons and tend to gain one electron to achieve a stable electron configuration. This similarity in chemical activity makes them both highly reactive and prone to forming compounds with other elements.

J.J. Thomson is the correct answer because he was the scientist who discovered that atoms contain negatively charged particles called electrons. He conducted experiments with cathode rays and proposed the "plum pudding" model of the atom, which suggested that electrons were embedded in a positively charged sphere. This discovery laid the foundation for our understanding of atomic structure and the existence of subatomic particles.

Ernest Rutherford is the correct answer because he conducted the famous gold foil experiment in which he bombarded a thin sheet of gold with alpha particles. He observed that most of the alpha particles passed straight through the gold foil, indicating that the atom is mostly empty space. However, a small fraction of the alpha particles were deflected at large angles, suggesting the presence of a dense, positively charged nucleus at the center of the atom. Rutherford's discovery revolutionized our understanding of atomic structure and led to the development of the nuclear model of the atom.

The group number on the periodic table corresponds to the number of valence electrons in an atom of an element. The group number represents the number of electrons in the outermost energy level or shell of an atom. Since valence electrons are the electrons involved in chemical bonding and determining the chemical properties of an element, the group number can be used to identify the number of valence electrons in an atom.

Group 13-16 is known as the "Mixed Groups" because it is a combination of different elements with varying properties and characteristics. These elements do not fit into a specific category like the alkali metals, alkaline earth metals, transition metals, halogens, or noble gases. Instead, they form a group that includes elements such as boron, carbon, nitrogen, oxygen, phosphorus, sulfur, and others. These elements have a diverse range of properties and behaviors, making them difficult to classify into a single group.

The given model is an example of Thompson's theory of the atom. This theory, proposed by J.J. Thompson, suggests that atoms are made up of positively charged particles called protons and negatively charged particles called electrons. According to this theory, electrons are embedded in a positively charged sphere, similar to the raisins in a plum pudding. This model helped to explain the existence of negatively charged particles in atoms and laid the foundation for further understanding of atomic structure.

The number of levels of electrons in an atom of an element can be identified from the period number. The period number in the periodic table represents the energy levels or shells of an atom. Each period corresponds to a specific number of electron shells, with the first period having one shell, the second period having two shells, and so on. Therefore, by looking at the period number of an element, one can determine the number of electron shells it has.

The Boron Group contains elements that can be found in all three states of matter: solid, liquid, and gas. This is because the elements in this group have varying melting and boiling points, allowing them to exist in different states under different conditions. For example, boron is a solid, aluminum is a solid, gallium is a liquid, and indium is a solid, while thallium is a solid but can also sublimate into a gas. Therefore, the Boron Group is the correct answer.