six hours it took the sample to reach 40mg by two. The answer will be three hours. a) Is incorrect because it equal 2 half-lives. 15. The smallest particle of an element that retains the characteristics of the element is a(n) A) atom. B) electron. C) nucleus. D) neutron. E) proton. The correct answer is A)‚ atom. According to page 105 an atom retains the characteristic of that element. b) Describes the negative charge of a particle. Even though it has no mass it is not considered the
Premium Atom Energy Chemistry
movement of electrons in atoms. Electrons exist in constant orbit around an atom’s nucleus in different levels of energy‚ also known as orbitals. When an electron makes the transition – drops - to a lower orbital‚ it needs to release some energy – which it does in the form of a photon. The energy level of this photon corresponds to how far the electron dropped between orbitals. So when a photon collides with another atom‚ the energy in the photon sometimes gets absorbed and boosts an electron in that
Premium X-ray Electromagnetic radiation Light
The polymerase chain reaction (PCR) is a biochemical technology in molecular biology used to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude‚ generating thousands to millions of copies of a particular DNA sequence. Developed in 1983 by Kary Mullis‚[1][2] PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications.[3][4] These include DNA cloning for sequencing‚ DNA-based phylogeny‚ or
Premium DNA Electric charge Electron
(substance that cannot be broken down into further substances) Atom (smallest unit of an element) – subatomic particles (neutrons‚ protons‚ electrons) Compound (2 or more) Atomic number - # of protons Atomic mass = # of neutrons and protons Ion – total number of electrons doesn’t equal # of protons (anion gained electrons‚ cation lost electrons) Electron shells‚ orbitals‚ valency‚ rule of 8 Bonds = ionic‚ covalent (polar‚ nonpolar)‚ hydrogen‚ Van der walls Electronegativity Relationship of
Premium Atom Molecule Acid
in the periodic table. Both the alkali metals and the halogens (nonmetals) on considered to be main group elements. When the number of outer shell electrons is closer to one or seven the higher the elements reactivity. Alkali metals contain a single electron in their outer shell which makes them highly reactive and halogens contain only seven electrons in their outer shell. Noble gases‚ such as helium‚ are not reactive because they are chemically stable and will not combine with other elements. H₂S
Premium Chemistry Periodic table Chemical element
Current ‚ Voltage‚ and Resistance [pic] A. The Electrical Nature of Matter All atoms are made up of protons‚ neutrons‚ and electrons. The classical model of the atom consists of a positively charged nucleus made up of protons and neutrons‚ and a number of negatively charged electrons in orbit about the nucleus. The simplest form of the model pictures electrons as tiny particles which circle the nucleus in definite orbits similar to the orbits of the planets about the sun. Though this model
Premium Electric charge Electric current Electron
through ordinary matter almost unaffected. The neutrino (meaning "small neutral one") is denoted by the Greek letter ν (nu). Neutrinos are similar to the more familiar electron‚ with one crucial difference: neutrinos do not carry electric charge‚ which means that they are not affected by the electromagnetic forces which act on electrons. Neutrinos are affected only by the weak sub-atomic force‚ of much shorter range than electromagnetism‚ and gravity‚ which is relatively weak on the subatomic scale
Premium Electron Neutron Elementary particle
charges repel‚ unlike charges attract. Electrons and protons have‚ to fantastic accuracy‚ equal and opposite charges. Quarks have 1/3 the electron charge but are never seen alone! In wires electrons do the moving to carry electrical current. In solutions or plasmas there can be positive charge carriers‚ ions or protons. Although the signal to tell electrons to move in wires travels at about 2/3 the speed of light (FAST in laymen’s terms) the electrons only travel at a person’s walking pace
Premium Electric charge Electric current Electron
Physics Folio Radioactivity Prepared By : Aniq Danial Bin Saharudin 5 Al – Hasseb Sekolah Menengah Sains Banting Contents No | Contents | Page | 1. | Appreciation | | 2. | Introduction | | 3. | Analysis : - Nucleus Of An Atom - Radioactive Decay - The Uses Of Radioisotopes - Nuclear Energy - The Importance Of Proper Management Radioactive
Premium Neutron Radioactive decay Electron
(1) 2.Calculate the number of lines when an electron jumps from 6th level to 2nd level. (1) 3. If two discharge tubes A and B are filled with Hydrogen and oxygen respectively‚ will the electrons and gaseous cations be the same? Justify your answer. (1) 4. Which
Premium Periodic table Alkaline earth metal Quantum mechanics