Atoms, The Nucleus And The Mole

Ions are formed by gaining or losing electrons. When an atom gains or loses one or more electrons, it becomes electrically charged and is called an ion. If an atom gains electrons, it becomes negatively charged and forms a negative ion or anion. Conversely, if an atom loses electrons, it becomes positively charged and forms a positive ion or cation. This process of gaining or losing electrons allows atoms to achieve a stable electron configuration and form ions with different charges.

The gold foil (or alpha scattering) experiment conducted by Ernest Rutherford resulted in the discovery of the nucleus. In this experiment, Rutherford bombarded a thin gold foil with alpha particles and observed their scattering patterns. He expected the alpha particles to pass straight through the foil or be slightly deflected, as per the prevailing model of the atom at the time. However, he observed that some alpha particles were deflected at large angles, and a few even bounced back. This led to the conclusion that the atom has a tiny, dense, and positively charged nucleus at its center, surrounded by mostly empty space.

The law of multiple proportions states that when two elements combine to form different compounds, the ratio of the masses of one element that combines with a fixed mass of the other element can be expressed in small whole numbers. In the case of H2O and H2O2, both compounds involve the combination of hydrogen and oxygen, but in different ratios. H2O has a 2:16 ratio of hydrogen to oxygen, while H2O2 has a 2:32 ratio. These ratios can be simplified to 1:8 and 1:16 respectively, showing that the masses of oxygen that combine with a fixed mass of hydrogen are in small whole number ratios.

Lithium will have the largest number of moles because it has the smallest molar mass among the given elements. Molar mass is the mass of one mole of a substance, and since the mass of lithium is the smallest, it will have the largest number of moles when compared to the other elements with larger molar masses.

Magnesium-24 is an isotope of magnesium with a mass number of 24. The charge of 2+ indicates that the atom has lost two electrons. Since magnesium has an atomic number of 12, it normally has 12 electrons. However, with a charge of 2+, it means that two electrons have been removed, leaving behind 10 electrons. Therefore, the correct answer is 10.

Boron-10 has an odd number of both protons and neutrons. It has 5 protons and 5 neutrons, making a total of 10 nucleons. The other options have an even number of either protons or neutrons. Helium-4 has 2 protons and 2 neutrons, lithium-7 has 3 protons and 4 neutrons, and carbon-13 has 6 protons and 7 neutrons. Therefore, boron-10 is the only option that fits the criteria of having an odd number of both protons and neutrons.

J.J. Thomson is credited with discovering the charge to mass ratio for electrons. He conducted experiments using cathode ray tubes and observed the deflection of the rays in the presence of electric and magnetic fields. Through his experiments, Thomson determined that the ratio of the charge of an electron to its mass is constant, regardless of the type of gas used in the cathode ray tube. This discovery laid the foundation for our understanding of the fundamental properties of electrons and their role in atomic structure.

In positron emission, a proton in the nucleus is converted into a neutron, resulting in a decrease in the atomic number by 1. This occurs because a positron, which is a positively charged particle, is emitted from the nucleus. The positron carries away one positive charge, causing the atomic number to decrease.

If you have three times the mass of carbon as you have helium, it means that the mass of carbon is three times greater than the mass of helium. Since the atomic mass of carbon is 12.01 g/mol and the atomic mass of helium is 4.00 g/mol, this implies that the number of carbon atoms is approximately equal to the number of helium atoms. This is because the mass of an element is directly proportional to the number of atoms present. Therefore, the correct answer is that you have nearly equal numbers of carbon atoms as helium atoms.