chemistry Flashcards
describe the structure of an atom
building blocks of life, contain 3 different types of subatomic particles.
protons and neutrons inside nucleus and electrons in shells surrounding nucleus
explain what is meant by a neutral atom
the number of protons is equal to the number of electrons
describe the charges on protons, neutrons and electrons
protons = positive, neutrons = no charge/ neutral and electrons = negative
describe how electrons are arranged in atoms
the electronic configuration for an elements is the arrangement of electrons in energy levels (or shells) around the nucleus of a neutral atom.
each energy level can hold a limited number of electrons, 2,8,8
explain how ions are formed
an ion is an atom or group of atoms that has an electrical charge either positive or negative. formed when atoms gain or lose electrons to obtain full outer shells to become stable
discuss why other shell electrons are important
determine atoms reactivity
explain the difference between cations and anions
cation- an atoms that loses electrons has more protons than electrons and so has a positive overall charge
anion- an atom that gains electrons has more electrons than protons and so has a negative overall charge
explain why metals form cations and non-metals form anions
metals lose electrons, non metals gain electrons
how do bonds form between ions?
when a metal cation and non-metal anion react together in a chemical reaction
state the laws of conservation of mass in chemical reactions
mass cannot be created or destroyed, mass of reactants =mass of products
describe the difference between a physical and chemical change
physical- change in state, can be reserved
chemical- new substance formed, difficult to reverse eg baking a cake, frying an egg
list experimental observations that indicate a chemical change
COBALT ( colour, odour, bubbles, appearance or disappearance of a solid, light or sound produced, temperature change
define the term rate when describing chemical reactions
how quickly reactants are turned into products
how can we change the rate of reaction
more successful collisions
factors that speed up rate of reaction
increased temperature, catalyst, increased surface area, increased concentration
