The arrangement of particles in an atom Protons and neutrons make up the main, dense, central nucleus in the centre of the atom. This is surrounded by electrons “orbiting” the main nucleus. The electron are in shells depending on their energy levels, as the most energetic are on the outer shells, because they need more energy to travel around a bigger “orbit” of the nucleus. These shells are full when a certain amount of atoms are in the shell; 2 in the first shell, 8 in the next shell, 8 in the third shell and so on. When the shells are full, the atom is unreactive.
Hypothesis I predict that if the concentration of Hydrochloric acid is increased by 20%, the rate of reaction will also increase by 20%. This is because more molecules of Hydrochloric acid will be present, meaning there will be more molecules to react with. For particles to react, they must collide with one another, but for a successful collision, there must be enough energy for them to react. This is known as activation energy. Activation energy is defined as “the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur”.
- soluble gases mix homogeneously. Lesson 13.2 The intermolecular bond concept: vapor pressure, viscosity, and surface tension are determined by strength of molecular attraction. electrons in a nonpolar molecule are constantly shifting about. Dispersion force - temporary dipole attractions that can occur between nonpolar molecules. dispersion forces occur frequently for short periods of time.
The energy released is in the form of increased kinetic energy of the product particles and any radiation emitted. The energy released in a nuclear fission is very much larger compared to the energy released in a chemical reaction. Spontaneous natural nuclear fission reactions very rarely occur. Nuclear fission reactions are normally initiated by bombarding the nucleus with slow neutrons or thermal neutrons of low energy of about 10-2 eV. Nuclear fussion: Nuclear fusion is the process in which two light nuclei combine to form a heavier nucleus.
Explain your reasoning. * An atom of Y would be smaller than X because the ionization levels are larger than X. The electrons of Y are bound to the nucleus stronger than the X electrons. 8.30. Periodic Properties II Consider two hypothetical elements, W and Z.
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.
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.
Expansion, an increase in the volume of a substance, usually due to the addition of heat to the substance. The heat causes the molecules of the substance to move farther apart, making the substance occupy more space. A loss of heat causes the opposite effect, known as contraction. Although most substances expand when heated, not all expand at the same rate. Aluminum, for example, expands twice as much as iron when both are heated the same amount.
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.
Hypothesis With increasing temperature of sodium thiosulphate the reaction rate will increase as well. Justification As the collision theory states for a chemical reaction to occur particles need to collide at a certain speed and angle. Increasing the temperature gives particles more energy, so they move faster. As they move faster more collisions happen, hence more successful collision, which increases the rate of the reaction1. Materials> Hydrochloric acid HCl(l)> Sodium triosulphate Na2S2O3(l)> 250 ml3 beaker> 50 ml3 conical flask> 2 x 25 ml3 measuring cylinder> Thermometer> Stop clock> Tea kettle> Blank card> Pen Variables Reaction time is the dependent variable, as it depends on the temperature of the solution.