Atoms-Molecules_studyguide09 - 10 1 Dr Lisa Chemistry Sheet...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 10 1 Dr Lisa Chemistry Sheet for Microbiologists! (you need all the help you can get!!) Atoms, Elements and Compounds The smallest unit of matter having the characteristics of a specific element is called an _________. All matter (bacteria, paper, plastic, soil, water, humans) is made of ____________. The central nucleus of an atom is made up of neutrally charged sub-atomic particles called ______________ and positively charged particles called ______________. Each one of these subatomic particles has a mass of ______________. The nucleus does not take part in reactions and is stable. Negatively charged subatomic particles called _______________ have virtually no mass & surround the nucleus in set arrangements according to their energy level called ____________. The stability of an atom depends on how many ______________ it has and how they are arranged. Electrons are important because they take part in _____________ reactions. Atoms always start out with a ___________ charge because there are always the same number of ____________ as _____________ before an atom undergoes a reaction. Each atom has its own specific position & symbol in the _____________ table. Elements are listed in order of their _____________________ and are arranged by their chemical properties. Atoms with the same atomic number will always react the same way. The atomic number tells you the number of __________ in an atom and also if the atom is neutral it will tell you the number of ____________ present before any reactions have occurred. Notice that next to each element there is a second, larger number called the ______________________. The atomic mass tells you the number of _____________ and _________________ present in the nucleus. The number and arrangement of electrons determines the __________ of an atom. Electrons are arranged in shells. The shell closest to the nucleus is the 1 st shell (lowest energy electrons) & will hold a maximum of ____ e-. The 2 nd shell will hold up to ______e-. When drawing the structure of an atom, you fill the 1 st shell first & when filled go on to fill the next…… Most biologically important atoms have fewer than three shells. Eg Carbon, atomic no. is 6, atomic mass is 12.011 therefore a neutral atom will have 6 protons, 6 electrons & 6 neutrons. The 1 st shell will have 2 e-, & the 2 nd (outermost) shell will not be full having only 4 e-. The outer most shell in any atom is known as the _____________ shell & determines the stability of any given atom. Atoms with ________ outermost shells are always stable & unreactive while those with ________ outermost shells are unstable. Chemists talk about the __________ rule. Why is neon (Ne 10, 20.179) stable?______________________________________________________ Atoms strive to become ___________ by achieving a full outer most shell. This process is called a ____________________ and may occur by gaining, losing or sharing electrons. The valency of an atom is the number of ______ which an atom needs to gain or lose to become stable. Atoms with 5 or more e- is the number of ______ which an atom needs to gain or lose to become stable....
View Full Document

Page1 / 10

Atoms-Molecules_studyguide09 - 10 1 Dr Lisa Chemistry Sheet...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online