Atoms, Elements And Compounds Quiz

The center of an atom is called the nucleus. The nucleus is made up of protons and neutrons, which are tightly packed together. It has a positive charge due to the presence of protons. Electrons orbit around the nucleus in specific energy levels or shells. The nucleus is responsible for the majority of the atom's mass and contains almost all of its positive charge.

The proton is positively charged because it carries a positive electrical charge. It is one of the fundamental particles that make up the atom, along with neutrons and electrons. Protons are found in the nucleus of an atom and have a charge of +1. This positive charge is balanced by the negative charge of electrons, which orbit around the nucleus.

The number of protons in an atom determines its atomic number, which is a unique identifier for each element. Oxygen has an atomic number of 8, indicating that it has 8 protons in its nucleus. Therefore, the correct answer is 8.

The first energy level, also known as the K shell, can hold a maximum of 2 electrons. This is because the first energy level consists of only one sublevel, the s sublevel, which can hold a maximum of 2 electrons. Each sublevel can hold a specific number of electrons, with the s sublevel being able to accommodate 2 electrons. Therefore, the correct answer is 2.

The space surrounding the nucleus in an atom contains electrons. Electrons are negatively charged particles that orbit the nucleus in specific energy levels or shells. They are much smaller and lighter than protons and neutrons, and they have a negative charge that balances the positive charge of the protons in the nucleus. The arrangement of electrons determines the chemical properties and behavior of an atom.

an ion is an atom that lost or gained an electron

The number of protons in an element's nucleus determines its atomic number, which is unique to each element. This means that no two elements can have the same number of protons. The number of protons also determines the element's chemical properties and its place in the periodic table. Therefore, the number of protons is what distinguishes one element from another.

The main elements that make up to 96% of the human body are carbon, nitrogen, oxygen, and hydrogen. These elements are essential for the formation of organic compounds such as carbohydrates, proteins, lipids, and nucleic acids, which are the building blocks of life. Carbon is the backbone of organic molecules, while nitrogen is crucial for protein synthesis. Oxygen is necessary for cellular respiration and energy production, and hydrogen is involved in various biochemical reactions. Calcium and iron are also important for the body, but they make up a smaller percentage compared to carbon, nitrogen, oxygen, and hydrogen.

Ionic bonds are formed between two ions that have lost and gained electrons. When an atom loses electrons, it becomes a positively charged ion called a cation. On the other hand, when an atom gains electrons, it becomes a negatively charged ion called an anion. The attraction between these oppositely charged ions leads to the formation of an ionic bond. In this type of bond, electrons are transferred from one atom to another, resulting in a stable, electrostatic attraction between the ions.