chapter 17

how many different elements are there

15 elements

how many electrons can the innermost shell of an atom have?

2 electrons

how many different elements are in a water molecule?

2 hydrogen, one oxygen

what kind of charge is on an atom that has fewer electrons than protons?

a net charge (positive)

when a nuclear is electrically natural, what is it called?

a neutron

to see a molecule you should use what kind of microscope?

an electron microscope

there are about as many atoms of air in our lungs at any moment as there are breathes if air in __________

atmosphere

protons, neutrons, and electrons combine to form what?

atoms

why are isotopes

atoms of the same elements having different number of neutrons

why can we sat that a granite block is mostly empty space?

bc its made up of atoms which are mostly empty space

how does the periodic table arrange the elements

by atomic number and electron arrangements

what do you get if you remove two protons from an oxygen nucleus

carbon

elements that are above or below each other in the periodic table have one more or one less

electron shell

in an electrically natural atom, the number of protons in the nucleus is balanced by an equal number of what other particle?

electrons

what particles do not exist in the nucleus

electrons

there are slightly more than 100 known atoms that combine to form all living and nonliving matter that we know about. what are these atoms called?

elements

assuming all the atoms exhaled by Julius Ceasr in his last dying breath are still in the atmosphere, about how often do you breathe one of those atoms?

every time you inhale

of the elements hydrogen, iron, lead and uranium, which has the most massive atom?

hydrogen

which element makes up over 90 percent of the known atoms in the universe?

hydrogen

what do you get if you add one neutron to a hydrogen nucleus?

hydrogen isotope

nuclei of atoms that make up a newborn baby were originally made where?

in ancient stats

nearly all the elements heavier than hydrogen that occur today were created where?

in the deeper interior of stars

where is most of the mass of an atom located? does this part of the atom also account for most of the atoms volume?

in the nucleus. no it doesn't since its less massive then trillionth of the volume

how many different molecules are there

infinte molecules

sometimes an atom has more or fewer electrons than it does protons. what is the name of such an atom?

isotope

which is the largest , a molecule atom proton or nuclus

molecule

atoms and molecules are in a state of constant agitation called what

molecules

atoms combine together to form what

molecules

is air a compound? why or why not

no bc age proponents of an atom vary

if we doubled the magnifying power of the most powerful optical microscope in the world would we be able to see atoms? why or why not

no bc the atoms are smaller than the wave lengths of visible light

at the center of every atom is a mass filled region. what is this region called?

nucleus

most of the matter if the universe is in which phase ?

plasma

what are the kinds of electric charge

positive, negative and natural

elements that are side by side in the periodic table have one more or one less

proton

which is the smaller, a molecule atom proton or nuclus

proton

what articles can be nucleons?

protons and neutrons

what determines how atoms combine to form molecules?

the arrangement of electrons

solid matter is mostly empty space. why don't solids fall through one another?

the molecules vibrate about fixed positions

what makes an element distinct

the number of protons

what defines the atomic number

the number of protons in the nucleus on an atom

what is brownian motion?

the perpetual jiggling of particles that are just large enough to be seen

are compounds always made of molecules?

they aren't always made of molecules

of the elements hydrogen, iron, lead and uranium, which has the most least massive atom?

uranium