1. Chemistry Basics for Food Science
what does the word atom mean?
"uncuttable" (Greek origin)
what is the atomic mass of Carbon? (simple answer)
*about* 12, because there are six protons and six neutrons
how many oxygen atoms does a water molecule have?
1
what is Hydrogen's atomic number and why?
1 because it only has one proton
what is the atomic mass of Carbon? (exact answer)
12.011, which is what you will see on the periodic table. This is because the number of protons + neutrons adds up to twelve in most cases. However, most elements have naturally occurring Isotope versions of themselves and some have "man made" Isotopes. The mass of each of these various Isotopes (versions of the same element with different numbers of neutrons) are averaged and that is the mass number you see on the periodic table.
How many electrons fit in the first shell?
2
how many hydrogen atoms does a water molecule have?
2
how many protons does Carbon have in its inner most shell?
2
how many atoms can Carbon bond with in its second shell?
4
how many protons does Carbon have in its second shell?
4
How many neutrons does Carbon have? (simple answer)
6
How many protons does Carbon have?
6
what is the atomic number of Carbon and why?
6, because it has 6 protons
How many electrons fit in the second shell?
8
How many electrons fit in the third shell?
8
what is a covalent bond?
A chemical bond formed when two atoms share electrons.
what is an ionic bond?
A chemical bond resulting from the attraction between oppositely charged ions (one atoms "steals" an electron from another, it does not want to share).
what is water?
A molecule
chemical reaction
A process during which chemical bonds between atoms are broken and new ones are formed. Producing one or more different molecules (substances).
What has more mass, an electron or a proton?
A proton. Electrons have (also called "carry" or "hold") much less mass.
what is an element?
A substance made of only one type of atom
what is the chemical symbol for gold?
AU
Why have I seen information referring to shells that have space for 18 electrons?
All elements on the periodic table with atomic numbers of 1 through 18, have shells with a 2-8-8 configuration. Elements above that begin to have more shells that has space for more electrons. You do not need to worry about that now. : )
what is matter?
All things, both visible (rock, you) and not visible (oxygen, nitrogen) are made of matter. Matter is made of atoms and molecules. Matter has mass.
what does a "full compliment" of electrons mean?
An atom that has an electron in every available space in its "rings" or "cloud" and there are no open spaces for more electrons.
what is an isotope?
An atom that is missing a neutron or has an extra neutron.
what is a proton?
An atomic particle that has a positive charge
neutron
An atomic particle that has no charge
Ion
An ion is referred to as a "charged" atom. It is charged because the number of electrons do not equal the number of protons in the atom. Ions are atoms that are either missing or have extra electrons.
atomic mass (simple answer)
Atomic mass is a measure of the size of an atom (not the weight). This size can be equal to the number of protons and neutrons in an atom.
what are the parts of an atom called when referred to a group, not individually?
Atomic particles and/or subatomic particles
what does at atom without a full compliment of elections want?
Atoms very much want to be happy and content with every spot for an electron taken so they seek out other atoms they can share electrons with or steal electrons from. Once they have a full compliment of electrons, they are happy and content.
why are atomic weights decimals?
Because the mass of each version of an element (atom) is averaged together to arrive at the atomic mass number listed on the period table. The mass of each of these various Isotopes (versions of the same element with different numbers of neutrons) are averaged and that is the mass number you see on the periodic table.
what is the term that means atoms hook to each other?
Bond
what is the atomic symbol of Carbon?
C
what is the chemical symbol for carbon?
C
How many neutrons does Carbon have? (complex answer)
Carbon has six neutrons *most* of the time. However, it is possible for Carbon atoms to have seven or eight neutrons. These extra neutrons turn a "regular" Carbon atom into an Isotope. You may see the term, "Carbon-14" which is a Carbon Isotope, but you don't need to worry about this higher level of chemistry yet. : )
Why is Carbon sometimes referred to as Carbon-12?
Carbon-12 is the most common form of the element of Carbon. Each atom has six protons and six neutrons thus it's called Carbon-12. There are also Carbon Isotopes, which have more than six neutrons and they are referred to with using terms as Carbon-14. You don't need to worry about this part of chemistry or Carbon at this time. : )
Which atomic particle has a negative charge?
Electron
why aren't electrons included in the calculation of the mass of an atom/element?
Electrons are so small, scientists decided not to include the in the mass calculation.
where are electrons located?
Electrons move around the nucleus of an atom. They move around in concentric layers that form "rings" or a "cloud" area around the nucleus of an atom.
what is Hydrogen's atomic symbol?
H
what is the chemical symbol for hydrogen?
H
what is the chemical symbol for water?
H2O
where are neutrons located?
In the nucleus of an atom
where are protons located?
In the nucleus of an atom
chemistry is the study of what?
Matter
define weight
Measurement of the gravitational pull on an object.
when atoms are bonded together, they are called
Molecules
is air an element?
No
is fire an element?
No
is there a limit to how many atoms can bond together?
No
is water an element?
No
is the atomic number the same as the atomic mass?
No, "atomic mass" is the atom's protons and neutrons added together and is expressed as a decimal number. Atomic numbers are not decimals, they are whole numbers.
do atoms always have the same number of neutrons and protons? (simple answer)
No, but many do
is water an atom?
No, it's a molecule
does a given atom (element) always have the same number of neutrons? (simple answer)
No, they do not always have the same number.
what is Oxygen's atomic symbol?
O
is gold a molecule?
Only if there are two or more gold atoms bonded together
what is an atom?
Smallest unit of matter.
what are the three states of matter?
Solid, liquid, gas
what is mass?
The amount of matter in an object.
what does it mean to say an atom is "stable"?
The atom has a "full compliment" of electrons, there are no open spaces for more electrons, so the atom is quite happy and content.
where can the atomic mass be found on the periodic table of elements?
The atomic mass is the decimal number at the bottom of each element
mass vs weight
The mass of an object is the same no matter where it is, the weight of an object can change depending on where it is (objects don't weigh the same on earth as they do on the moon due to different gravitational forces).
atomic number
The number assigned to an atom/element on the Periodic Table. It represents the number of protons in an atom. The number of protons determines the atom's chemical properties and its placement on periodic table.
what does an atom with extra electrons want?
These atoms are generous and kind and like to give up their electrons to another atoms who needs it to have a full compliment and thus be happy and content.
True or False? An Ion or an Isotope is still the same atom and the same element, they are just a little different from every other atom of the same element.
True
what is a molecule?
Two or more atoms bonded together.
Is an atom still the same element if it is missing a neutron or has an extra neutron (such as an isotope)?
Yes
Is an atom still the same element if it is missing an electron or has an extra electron (such as an ion)?
Yes
can Carbon form double bonds?
Yes
can atoms of different types bond together?
Yes
can atoms of the same type bond together?
Yes
is carbon an atom?
Yes
is carbon an element?
Yes
is gold an atom?
Yes
is gold an element?
Yes
is hydrogen an atom?
Yes
is hydrogen an element?
Yes
does a given atom (element) always have the same number of protons?
Yes, each atom of any given element will always have the same number of protons.
What? I don't get this Isotope and averaging to get the atomic mass number thing. It's confusing!
Yes, it can be. Let's look at another example, Bromine. Bromine (Br), at atomic number 35, has a greater variety of Isotopes than Carbon. The atomic mass of Bromine (Br) is 79.90. There are two main Isotopes at 79 and 81, which average out to the 79.90amu value. The 79 has 44 neutrons and the 81 has 46 neutrons. While it won't change the average atomic mass, scientists have made bromine isotopes with masses from 68 to 97. It's all about the number of neutrons. As you move to higher atomic numbers in the periodic table, you will probably find even more isotopes for each element.
what is an element
a single atom, or a molecule made of up of only a single type of atom. The molecule can be three atoms or three million atoms bonded together, it is still an element if there is only one type of atom present.
what are the two types of atomic bonds you have learned about?
covalent and ionic
give an example of matter in each form (don't use water)
rock, plastic (solid) milk, urine nitrogen, helium (gas)