2022年9月11日 · The symbol of the element helium is He, its proton number is 2, its atomic mass is 4, its neutron number is 2 and finally; helium belong to period 1 of the periodic table. However, helium is a noble gas, meaning it has a stable octet electronic configuration ( having 8 …

2024年12月26日 · The mass number of this helium isotope (Helium-4) is calculated by adding the number of protons and neutrons, resulting in a mass number of 4. Key Points. Helium has an atomic number of 2. Helium typically has two neutrons, making it the most common form, Helium-4. The atom’s electrons equal the number of protons, maintaining neutrality.

2019年1月1日 · The rounded atomic mass of helium is 4.003 amu. The mass of an He atom is slightly less than the combined masses of its constituent subatomic particles, which is known as the mass defect. The mass lost in the transformation from hydrogen atoms to helium atoms is converted into energy during the fusion reaction. Learn more about atomic mass of ...

2016年9月20日 · Each element has a unique atomic number and atomic mass. Atomic Number: Helium has an atomic number of 2. This means that every helium atom has 2 protons in its nucleus. Atomic Mass: The atomic mass of helium is approximately 4 atomic mass units (amu). This atomic mass accounts for the number of protons and neutrons in the nucleus.

2024年8月22日 · Helium (He): The atomic mass is about 4.0026 g/mol. Boron (B): The atomic mass is roughly 10.81 g/mol. Nitrogen (N): The atomic mass is approximately 14.01 g/mol. From the list, Boron (B) has the greatest atomic mass of approximately 10.81 g/mol. For question 8, we need to identify which element is classified as a metal: Carbon (C): Non-metal ...

2017年8月8日 · The atomic number of an element is the number of protons in its nucleus, while the mass number is the total of protons and neutrons. For helium-4, the atomic number is 2 and the mass number is 4. The atomic number also tells us the number of electrons in a neutral atom, which in the case of helium, is also 2.

2017年12月1日 · Helium-4 is the more abundant isotope of helium, comprising about 99.9999% of naturally occurring helium. In contrast, helium-3 is much rarer, accounting for only about 0.0001% of helium found in nature. The average atomic mass of helium reflects this abundance, being closer to the mass of helium-4.

2023年6月24日 · The average mass of an atom is measured in atomic mass units (amu) or grams. To calculate the average mass of one helium atom, we need to refer to the periodic table. The atomic mass of helium (He) is approximately 4.0026 amu. To convert amu to grams, we use the conversion factor 1 amu = 1.66 x 10^-24 grams.

2023年10月6日 · The mass of one mole of helium gas is 4.00 grams, derived from its atomic mass unit and the concept of molar mass. The correct option is B) 4.00 g. Explanation: The subject of the student question is about the mass of one mole of helium gas. This is derived from the fact that the atomic mass unit (u) of helium is approximately 4 u.

2021年11月20日 · The atomic number of helium is 2, and it refers to the number of protons in the nucleus. Explanation: 2. Atomic Mass and Neutrons. The atomic mass of helium is 4.0026 atomic mass units (amu). It is determined by adding up the masses of protons and neutrons in the atom's nucleus. Since helium has an atomic number of 2, it has 2 protons.