Biochemistry unit test section 1

what do all atoms of the same element have in common?

# of protons

neutrons

# varies slightly among atoms of the same element

mass of protons and neutrons

1 amu (atomic mass unit)

What is H20 made up of?

2 atoms of hydrogen and 1 atom of oxygen

how many electrons can the first energy level hold?

2 electrons

how many atoms are in C6H1206?

24 atoms

how many atoms are in BO2?

3 atoms

how many atoms are in NH3?

4 atoms

the atomic number is 6, how many protons are there?

6

how many electrons can levels 2-7 hold?

8 electrons( octet rule)

Neutron formula

N=AM-AN (atomic mass-atomic #)

volume

The amount of space an object occupie

compound

a pure substance made up of atoms of two or more elements

how do you find the atomic mass of an atom?

add the # of protons and neutrons in an atom

ion

an atom or molecule w/ a net electric charge due to the loss or gain of 1 or more electrons

matter

anything that has mass and volume (everything in the universe is composed of it)

negative ions

atoms that gain electrons

positive ions

atoms that lose electrons

Coefficient

before a formula; tells the # of molecules

What happens in a chemical reaction?

bonds are broken, atoms are rearranged, and new chemical bonds are formed

How are elements arranged on the periodic table?

by atomic number

nucleus

central core of an atom(positively charged)

how are isotopes of the same element produced?

different # of neutrons

unique chemical symbol

each element has one; consists of 1-2 letter and first letter is always capitalized

nonpolar covalent bond

equal sharing of electrons "double bond" (ex: 02)

covalent bond

formed when two atoms share one or more pairs of electrons

electron cloud

general area where electrons are located

why do atoms tend to react/combine with other atoms?

in order to become more stable

How many elements are there?

more than 100(92 naturally occurring)

electrons

negatively charged high energy particles with little or no mass

where are protons and neutrons found?

nucleus of an atom

do outer or inner levels of the nucleus have more energy?

outer energy levels

valence electrons

outermost number of electrons

what is 90% of the mass of an organism?

oxygen, carbon, hydrogen, nitrogen

What does the nucleus contain?

positively charged protons and neutral neutrons(also contains most of an atoms mass)

Element

pure substance that can't be broken down chemically into simpler kinds of matter

mass

quantity of matter an object has

chemical formula

shows the kind and proportion of atoms of each element that occurs in a particular compound

element that is likely to form ionic bonds

sodium

Subscrpit

tells the # of molecules of each element (after a symbol)

ionic bonds

the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions.(some atoms become stable by losing or gaining electrons)

atomic mass

the number of protons and neutrons added together

atomic number

the number of protons in the nucleus of an atom

what happens if the # of protons are balanced by an equal # of negatively charged electrons?

the overall charge is neutral

molecules

the smallest part of a compound that have all the properties of the compound

atoms

the smallest part of an element that retains all the properties of that element

polar covalent bond

unequal sharing of electrons (ex: H20)

how many energy levels can atoms have?

up to 7 energy levels (1 is closet to nucleus and 7 is farthest)

Example of a compound

water

When are atoms most stable?

when their outermost energy level l is full