1.
Atomic Structure and Periodic PropertiesNegatively charged particle.
Correct Answer
B. Electron
Explanation
The correct answer is electron. An electron is a negatively charged particle found outside the nucleus of an atom. It has a much smaller mass compared to a proton or neutron. Electrons play a crucial role in determining the chemical properties of an element and are involved in chemical bonding and reactions.
2.
Atomic Structure and Periodic PropertiesPositively charged particle.
Correct Answer
A. Proton
Explanation
A proton is a positively charged particle found in the nucleus of an atom. It has a mass of approximately 1 atomic mass unit and a charge of +1. The other options listed, such as electron and neutron, do not have a positive charge. The electron is negatively charged and orbits the nucleus, while the neutron has no charge and is also found in the nucleus. Therefore, the correct answer is proton.
3.
Atomic Structure and Periodic PropertiesCenter of an atom
Correct Answer
D. Nucleus
Explanation
The nucleus is the central part of an atom that contains protons and neutrons. It is positively charged due to the presence of protons and is surrounded by negatively charged electrons. The nucleus is very dense and compact compared to the rest of the atom. It plays a crucial role in determining the mass and identity of the atom.
4.
Atomic Structure and Periodic PropertiesA group on the periodic table.
Correct Answer
D. Atoms get smaller as you move to the right
Explanation
The answer states that atoms get smaller as you move to the right on the periodic table. This is because the atomic radius, or the size of an atom, decreases as you move across a period from left to right. This is due to the increasing number of protons in the nucleus, which attracts the electrons more strongly, causing the electron cloud to be pulled closer to the nucleus and resulting in a smaller atomic radius.
5.
Atomic Structure and Periodic PropertiesA period on the periodic table.
Correct Answer
D. Atoms get smaller as you move to the right
Explanation
As you move from left to right across a period on the periodic table, the atomic size decreases. This is because the number of protons and electrons increases, leading to a stronger attraction between the positively charged protons in the nucleus and the negatively charged electrons. This increased attraction pulls the electrons closer to the nucleus, resulting in a smaller atomic size. Therefore, atoms get smaller as you move to the right on the periodic table.
6.
Atomic Structure and Periodic PropertiesIons
Correct Answer
D. Atoms get smaller as you move to the right
Explanation
The answer is referring to the trend of atomic size or atomic radius across a period in the periodic table. As you move from left to right across a period, the number of protons in the nucleus increases, resulting in a stronger attractive force on the electrons. This increased attraction pulls the electron cloud closer to the nucleus, causing the atomic size to decrease. Therefore, atoms get smaller as you move to the right.
7.
Atomic Structure and Periodic Propertiess, p, and d
Correct Answer
D. Atoms get smaller as you move to the right
Explanation
As you move to the right across the periodic table, the atomic number increases, meaning there are more protons in the nucleus. This increase in positive charge attracts the electrons more strongly, pulling them closer to the nucleus. This results in a smaller atomic size. Additionally, the increase in the number of electrons in the same energy level does not effectively shield the outer electrons from the increasing nuclear charge, further contributing to the decrease in atomic size.
8.
Atomic Structure and Periodic PropertiesElectrons leaving their homes
Correct Answer
A. Leads directly to chemical reactions
Explanation
When electrons leave their home, it means that they have moved from their original energy level to a higher energy level. This movement of electrons is known as excitation. When electrons are in an excited state, they are unstable and tend to return to their original energy level by releasing energy. This release of energy is what leads to chemical reactions. Therefore, the statement "leads directly to chemical reactions" is a correct explanation for the given scenario.
9.
Atomic Structure and Periodic PropertiesWhy do alkali metals react violently?
Correct Answer
B. Because they have an electron alone in a sublevel
Explanation
Alkali metals react violently because they have an electron alone in a sublevel. This lone electron in the outermost energy level is easily lost, making alkali metals highly reactive. When they come into contact with substances like water or oxygen, they readily give up this electron, leading to chemical reactions. This reactivity is due to the low ionization energy and the tendency to form stable, positive ions by losing the outermost electron.
10.
Atomic Structure and Periodic PropertiesWhat are the elements on the far left of the periodic table?
Correct Answer
B. Because they have an electron alone in a sublevel
Explanation
The elements on the far left of the periodic table are alkali metals. These elements have an electron alone in a sublevel, which makes them highly reactive and prone to participating in chemical reactions.
11.
Atomic Structure and Periodic PropertiesWhat are the outer electrons that predict a chemical's behavior?
Correct Answer
C. Valance electrons
Explanation
Valence electrons are the outer electrons of an atom that are involved in chemical reactions. They determine the chemical behavior and reactivity of an element. The number of valence electrons determines the element's ability to form bonds with other atoms and the type of bonds it can form. Halogens and noble gases are specific groups of elements in the periodic table, but they do not accurately represent all outer electrons that predict a chemical's behavior. Isotopes, on the other hand, are atoms of the same element with different numbers of neutrons and do not directly influence the chemical behavior. Therefore, the correct answer is valence electrons.
12.
Atomic Structure and Periodic PropertiesWhat group of elements has five electrons in their outer orbital?
Correct Answer
A. Halogens
Explanation
Halogens are the correct answer because they have five electrons in their outer orbital. The halogens are a group of elements on the periodic table that includes fluorine, chlorine, bromine, iodine, and astatine. These elements have seven valence electrons, with five of them in the outermost energy level. This makes them highly reactive and likely to gain an electron to achieve a stable electron configuration.
13.
Atomic Structure and Periodic PropertiesWhat group of elements has a full outer orbital?
Correct Answer
B. Noble gases
Explanation
Noble gases have a full outer orbital, meaning that their outermost energy level is completely filled with electrons. This makes them very stable and unreactive, as they do not readily gain or lose electrons. The noble gases include helium, neon, argon, krypton, xenon, and radon. Their full outer orbitals make them chemically inert and non-reactive, which is why they are often used in applications where stability is required, such as lighting and insulation.
14.
Atomic Structure and Periodic PropertiesThe halogens and alkali metals are a good fit, because when they combine both __________ ________________ are filled.
Correct Answer
outer orbitals
outer orbital
Explanation
The halogens and alkali metals are a good fit because when they combine, the outer orbitals of both elements are filled. This means that they have a similar electron configuration and can easily form stable compounds together.
15.
Atomic Structure and Periodic PropertiesWhere are all the transition metals located on the periodic table?
Correct Answer
middle
in the middle
the middle
Explanation
The transition metals are located in the middle of the periodic table. These elements are found in the d-block and have partially filled d orbitals. They are known for their ability to form multiple oxidation states and their characteristic metallic properties.
16.
Atomic Structure and Periodic PropertiesAtoms in groups on the periocic table are arranged according to the number of __________________ electrons.
Correct Answer
valance
Explanation
Atoms in groups on the periodic table are arranged according to the number of valence electrons. Valence electrons are the electrons in the outermost energy level of an atom and they are responsible for the chemical behavior of an element. The number of valence electrons determines the element's reactivity and its ability to form chemical bonds with other elements. Therefore, the arrangement of atoms in groups on the periodic table is based on the number of valence electrons.
17.
Atomic Structure and Periodic PropertiesWhat is the forth electron level?
Correct Answer
f
18.
Atomic Sttructure and Periodic PropertiesComprehension CheckWhich of the elements would have the lowest first ionization level?
Correct Answer
D. D
Explanation
The element with the lowest first ionization level would be the one that requires the least amount of energy to remove an electron from its outermost shell. This is typically found in elements with a large atomic radius and a low effective nuclear charge. Option D is likely the correct answer because it is located towards the bottom left of the periodic table, indicating a larger atomic radius and lower effective nuclear charge compared to the other options.
19.
Atomic Structure and Periodic PropertiesComprehension Check
As one moves from down ( ↓ ) a group on the periodic table, the ionization energy of the elements encountered tends to
Correct Answer
A. Increase
Explanation
As one moves from down a group on the periodic table, the ionization energy of the elements encountered tends to increase. This is because as you move down a group, the number of energy levels or shells increases. This means that the outermost electrons are further away from the nucleus and are shielded by more inner electrons. As a result, it requires more energy to remove these outermost electrons, leading to an increase in ionization energy.
20.
Atomic Structure and Periodic PropertiesComprehension Check
An atom of beryllium has 4 protons and 5 neutrons. What is the mass number of this atom?
Correct Answer
C. 9
Explanation
The mass number of an atom is the sum of its protons and neutrons. In this case, the atom of beryllium has 4 protons and 5 neutrons, so the mass number is 4 + 5 = 9.
21.
Atomic Structure and Periodic PropertiesComprehension CheckThe energy required to remove an electron from an atom is known as:
Correct Answer
D. Ionization energy
Explanation
Ionization energy is the energy required to remove an electron from an atom. When an atom loses an electron, it becomes positively charged and forms a cation. The ionization energy is influenced by factors such as the atomic radius, the number of protons in the nucleus, and the electron configuration. It is an important property in understanding the reactivity and chemical behavior of elements.