true or false?
the number of electrons in an atom typically equal the number of protons so they tend to be electronically neutral?
true
define element
an element is matter composed of the same atoms, such as gold which only has gold atoms
define atomic number
the number of protons in their nuclei
how many protons does hydrogen have?
1 proton
how many protons does carbon have?
6 protons
how many protons does oxygen have?
8 protons
what does the term atomic mass mean?
the sum of the masses of its protons, neutrons and electrons
what are isotopes?
when the number of neutrons in the nuclei is different even though it is the same element. example is carbon 12 which has 6 protons and 6 neutrons and carbon 13 which also has 6 protons but has 7 neurtons
what makes isotopes unstable?
the ratio or protons and neurtrons which release energy and subatomic particles such as neutrons, protons and electrons
what are radioactive isotopes?
atoms that undergo radioactive decay
true or false?
the nuclei of an atom determines their identity?
true
what determines the chemical behavior of an atom?
the number of electrons they carry
what is the part/s of atoms that interact with each other?
the electrons
how many electrons do atoms need to be stable?
8 electrons
what constitutes positive valence?
when atom has extra electrons to give
what constitutes negative valence?
when the atoms need spaces to be filled
true or false?
molecules are composed of two or more atoms
true
define what is a compound?
a compound is composed of two or more elements
define inert gases
gases that do not create chemical bonds
define covalent bonds
sharing a pair of electrons by two atoms
define double covalent bonds
two convalent bonds between two atoms
define electronegativity
the attraction of an atom for electrons, the greater the pull the more electrons it can pull away from other atoms and the smaller the atom gets because the negative electrons are pulled by the protons closer together
define nonpolar covalent bond
no negative or positive pulls from the atoms
define polar covalent bond
when the electronegativity of one atom is greater than another atoms and the shared electrons spends more time with the atom with greater electronegativity causing that atom to become slightly negative and the weaker atom slightly positive
define ions?
an atom or group of atoms which have either a full positive charge or full negative charge
define cation?
a positively charged atom
define anions
a negatively charged atoms
define ionic bonds
the attraction between cation and anions which creates a positive and negative bond
do ionic bonds share electrons?
no, they are attracted via positive and negative charged atoms
what are electrolytes?
when cations and anions disassociate from one another in water molecules which allow it to conduct electricity
define hydrogen bonds
the electrical attraction between positive and negative charge on the same molecule or different molecules
true or false?
hydrogen bonds share atoms?
false they do not share atoms to bond them, they are electrically attracted to each other
true or false?
hydrogen bonds are stronger than covalent bonds?
false, they are weaker
define synthesis reactions
the formation of larger more complex molecules
define dehydration
the synthesis of two smaller molecules being joined together by a covalent bond and a water molecule is also formed
true or false? reactions that require energy are said to be endothermic reactions?
true they are endothermic because they require energy and trap it withing new molecular bonds
what is the definition of anabolism
the sum chemical reactions in an organism
define decomposition reactions
the reverse of synthesis, its the breaking the bonds of large molecules to produce smaller molecules
what is meant by exothermic?
reactions that release energy
what are endothermic reactions
reactions that trap energy
what is catabolism?
collectively all the decomposition reactions in an organism
what is metabolism?
the total chemical reactions in an organism including catabolic, anabolic and exchange reactions
