When the shells are full, the atom is unreactive. 3. How the numbers of the different sub-atomic particles determine the properties of the atom and the position of the element of the periodic table. The main nucleus of an atom is made of protons and neutrons. These added together make the relative atomic mass.
Electromagnetism Everything is made out of atoms. Atoms consist of a nucleus (containing neutrons and protons) and a cloud of electrons surrounding the nucleus. Protons are positively charged and electrons are negatively charged. If an object has more protons than neutrons, then it is negatively charged. If an object has more electrons than protons, then it is positively charged.
The electrons of an atom are bound to the nucleus by the electromagnetic force. A group of atoms can remain bound to each other by chemical bonds based on the same force, forming a molecule. An atom containing an equal number of protons and electrons is neutral; otherwise it is positively or negatively charged and is known as an ion. An atom is classified according to the number of protons and neutrons in its nucleus the number of protons controls the element, and the number of neutrons determines the isotope of the element. A molecule is an electrically neutral group of two or more atoms held together by chemical bonds Molecules are recognized from ions by their lack of
As long as the electronegativity difference is no greater than 1.7, the atoms can only share the bonding electrons. An example of a covalent bond would be water, its two hydrogen atoms with one oxygen atom (H2O). If two atoms differ considerably in their electronegativity than one of the atoms will lose its electron to the other atom. This results in a positively charged ion (cation) and negatively charged ion (anion). The bond between these two ions is called an ionic bond.If the electronegativity difference is greater than 1.7 then the higher electronegative atom has an electron attracting ability which is large enough to force the transfer of electrons from the lesser electronegative atom.
Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle. 6. A pulsar does not pulse, it emits beams of radiation that sweep around the sky as the neutron star rotates, and astronomers detect pulses when they sweep over the Earth. 11. Sometimes in binary systems, mass flows into a hot accretion disk around the neutron star and causes the emission of x rays.
David Kemp OCR Chemistry A Unit 1: F321 Atomic Structure (a) describe protons, neutrons and electrons in terms of relative charge and relative mass; Proton +1 1 Neutron 0 1 Electron -1 1/2000 Relative Charge Relative Mass (b) describe the distribution of mass and charge Within an atom; Positively charged Nucleus containing most of the mass, surrounded by atomic shells with orbiting electrons of negative charge and negligible mass. (c) describe the contribution of protons and neutrons to the nucleus of an atom, in terms of atomic (proton) number and mass (nucleon) number. The atomic number of the nucleus, also the proton number, shows the number of protons in the nucleus. It also defines the element. The number of neutrons added to the number of protons is the nucleon number or mass number.
INTRODUCTION TO NUCLEAR REACTION: The main features of nuclear reactions include radioactive decay, nuclear fission and nuclear fusion. Radioactive decay: Energy is released in a radioactive decay in the form of the kinetic energy of the particle emitted (α and β), the kinetic energy of the daughter nucleus and the energy of the gamma-ray photon that may accompany the decay. The energy involved may be calculated by finding the mass defect of the reaction. The energy released is the energy equivalent of the mass defect of the reaction. Nuclear fission: Nuclear fission is the process in which a large nucleus breaks into two smaller nuclei that are almost equal in mass.
The atomic masses of two isotopes of cobalt are 59 and 60. a) What is the number of protons and neutrons in each? • The protons are the same otherwise it wouldn't be cobalt = 27 So the remainders are neutrons = 32 or 33 b) What is the number of orbiting electrons in each when the isotopes are electrically neutral? • Electrons = protons = 27, if electrically
Atoms and Ions Atoms have no net charge. They are neutral. Ions have a charge, either positive or negative. A positive ion has more protons than electrons. CATION A negative ion has more electrons than protons.
The nucleus is surrounded by circling electrons on the outer shell. In most cases, atoms are neutrally charged (there is the same number of electrons as protons). If an atom has more electrons than protons, it is negatively charged. If an atom has more protons than electrons, it is positively charged. Static electricity is produced from a process known as triboelectrification.