Atomic Theory & Periodic Table Quiz

Valence electrons are found in the outer level of electrons. These are the electrons located in the highest energy level or shell of an atom. Valence electrons play a crucial role in chemical bonding as they are involved in the formation of chemical bonds with other atoms. The number of valence electrons determines the reactivity and chemical properties of an element.

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

The above element is a member of the Noble Gases group/family. Noble gasses are a group of elements in the periodic table that are characterized by their low reactivity and full valence electron shells. They are located in Group 18 of the periodic table and include elements such as helium, neon, argon, krypton, xenon, and radon. These elements have a stable electron configuration and do not readily form compounds with other elements.

Protons are positively charged particles that are found within 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 found in the nucleus, the electron cloud is where electrons are located. Therefore, the correct answer is the nucleus.

Neutrons are found in the nucleus of an atom. The nucleus is the central part of an atom that contains protons and neutrons. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. Neutrons play a crucial role in determining the stability and mass of an atom. They help to hold the nucleus together by counteracting the repulsive forces between the positively charged protons. Therefore, the correct answer is nucleus.

The charge of an electron is negative. Electrons are subatomic particles that orbit the nucleus of an atom and carry a negative charge. This charge is equal in magnitude but opposite in sign to the positive charge of a proton, which is the other subatomic particle found in the nucleus. The negative charge of electrons is essential for the stability and functioning of atoms and is a fundamental concept in the study of electricity and magnetism.

Neutrons are electrically neutral particles. They do not possess a positive or negative charge like protons or electrons, respectively. Neutrons have a mass similar to that of protons, but they lack any net charge, making them electrically neutral. This means that the number of protons and neutrons in an atom determines its overall charge.

The atomic number of an element tells you the number of protons and electrons in a neutral atom. Protons are positively charged particles found in the nucleus of an atom, while electrons are negatively charged particles that orbit around the nucleus. The atomic number represents the number of protons in an atom, which also determines the element's identity. Since atoms are neutral, the number of protons is equal to the number of electrons. Therefore, the atomic number provides information about both protons and electrons in an atom.

The correct formula to determine the number of neutrons in an atom is by subtracting the atomic number from the mass number. This is because the mass number represents the total number of protons and neutrons in the atom, and the atomic number represents the number of protons. By subtracting the atomic number from the mass number, we can isolate the number of neutrons in the atom.

Vertical columns on the periodic table are called groups. Groups are the columns that contain elements with similar chemical properties and the same number of valence electrons. The elements within a group have similar reactivity and tend to form similar types of compounds. The group number indicates the number of valence electrons in the elements within that group.

Electrons are found in the electron cloud, which is the region surrounding the nucleus of an atom. The electron cloud is where electrons exist and move around in specific energy levels or orbitals. It is a probabilistic model that represents the likelihood of finding an electron in a particular location around the nucleus. The electron cloud plays a crucial role in determining the chemical and physical properties of an atom.

Group 1 elements are known as alkali metals because they are highly reactive and easily lose their outermost electron to form a positive ion. They are also soft and have low melting and boiling points. Alkali metals include elements such as lithium, sodium, potassium, and cesium. They are typically found in compounds rather than in their pure form in nature.

Most of the elements on the periodic table are metals. This is because metals are the largest category of elements and they make up the majority of the periodic table. Metals are known for their shiny appearance, good conductivity of heat and electricity, malleability, and ductility. They are typically found on the left side and in the middle of the periodic table. Examples of metals include iron, copper, gold, and aluminum.

Nitrogen is not a solid because it is a gas at room temperature and pressure. It exists as diatomic molecules (N2) and has a boiling point of -195.8 degrees Celsius (-320.4 degrees Fahrenheit) at atmospheric pressure.

Period 3 on the periodic table consists of 8 elements. Each period represents a different energy level, and period 3 corresponds to the third energy level. The energy level determines the number of orbitals available for electrons, and each orbital can hold a maximum of 2 electrons. Therefore, the maximum number of electrons that can occupy the third energy level is 8.

The group number of an element on the periodic table indicates the number of valence electrons it has. Valence electrons are the electrons in the outermost energy level of an atom and are responsible for the chemical behavior of the element. Therefore, by knowing the group number of an element, one can determine the number of valence electrons it possesses.

Groups 3-12 elements in the periodic table are known as transition metals. These elements are characterized by their ability to form stable ions with partially filled d orbitals, which allows them to exhibit a wide range of oxidation states and form complex compounds. Transition metals are typically good conductors of heat and electricity, have high melting and boiling points, and are often used in various industrial applications such as catalysts, magnets, and electrical wiring.

Selenium is an element with atomic number 34. It has 6 electrons in its outermost orbital. The outermost orbital of an atom is called the valence shell, and it determines the chemical behavior of the element. In the case of Selenium, its valence shell is the 4th energy level, which can hold a maximum of 8 electrons. However, Selenium only has 6 electrons in its valence shell, making it more likely to gain 2 electrons to achieve a stable electron configuration.

Group 18 elements are known as the Noble Gases. Noble gasses are a group of elements on the periodic table that are characterized by their low reactivity and full outer electron shells. They are called noble gasses because they were once believed to be completely inert and noble, meaning they did not react with other elements. The noble gasses include helium, neon, argon, krypton, xenon, and radon. They are used in various applications such as lighting, lasers, and cryogenics.

Group 17 elements are known as the halogens. The halogens are a group of highly reactive nonmetals that include elements such as fluorine, chlorine, bromine, iodine, and astatine. They have seven valence electrons and are located in Group 17 of the periodic table. Halogens readily form compounds with metals and are known for their strong oxidizing properties. They have a tendency to gain one electron to achieve a stable electron configuration.

Bromine is a nonmetal and a liquid at room temperature and atmospheric pressure. It is the only element among the options that fits both criteria. Mercury is a liquid but it is a metal, not a nonmetal. Gallium is a metal and it is solid at room temperature. Hydrogen is a nonmetal but it is a gas at room temperature. Therefore, the correct answer is Bromine.

Ductile is the correct answer because if an element can be drawn into thin wire, it means that it can undergo plastic deformation without breaking. This property is known as ductility. Ductile materials can be stretched or pulled into long, thin wires without losing their strength or breaking. Weak refers to a 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.

Niels Bohr is the correct answer because he proposed the Bohr model of the atom, which states that electrons travel in specific paths or orbitals around the nucleus. This model revolutionized our understanding of atomic structure and provided a more accurate description of electron behavior than previous models proposed by J.J. Thomson, Ernest Rutherford, and John Dalton. Bohr's work laid the foundation for the development of quantum mechanics and earned him the Nobel Prize in Physics in 1922.

Ernest Rutherford is the correct answer because he is the scientist who proposed the concept of the atomic nucleus. He conducted the famous gold foil experiment in which he discovered that atoms have a small, dense, positively charged center called the nucleus. Rutherford's experiment provided evidence that most of the mass of an atom is concentrated in the nucleus, while the rest of the atom is mostly empty space. He also named the positively charged particles in the nucleus as protons.

The above element belongs to period 1.

Alkali metals are known to be extremely reactive with water. When alkali metals come into contact with water, they undergo a vigorous reaction, releasing hydrogen gas and forming metal hydroxides. This reactivity is due to the low ionization energy and the presence of only one valence electron in the outermost shell of alkali metals. This electron is easily lost, leading to the formation of positive ions, which then react with water to produce hydroxide ions.

Ionization energy is the energy required to remove an electron from an atom. As you move from left to right across a period, ionization energy increases due to the increasing effective nuclear charge, which holds electrons more tightly.

The correct answer is Thompson's. This is because the model mentioned in the question refers to J.J. Thompson's atomic model, also known as the "plum pudding" model. In this model, the atom is depicted as a positively charged sphere with negatively charged electrons embedded within it, resembling plums in a pudding. This model was proposed in the early 20th century and was later disproved by Rutherford's gold foil experiment.

Halogens are the group of elements that contain elements found in all three states of matter. This is because halogens consist of elements such as chlorine, bromine, and iodine, which can exist as gasses, liquids, or solids under normal conditions. Chlorine is a gas, bromine is a liquid, and iodine is a solid. Therefore, the halogens group contains elements found in all three states of matter.

The period number in the periodic table represents the number of energy levels or electron shells in an atom. Each period corresponds to a specific energy level, with the first period having only one energy level, the second period having two energy levels, and so on. Therefore, by identifying the period number of an element in the periodic table, one can determine the number of energy levels that its electrons occupy in the atom.