The Nitrogen Cycle
Which step of the Nitrogen cycle captures Nitrogen from the atmosphere and begins the process of making it usable by living things?
Nitrogen Fixation
True or false?
Chemical bonds are made by electrons.
True
What is the pH number for a neutral substance?
7
What does the atomic number tell us about an element?
The number of protons in 1 atom of the element
How do you calculate the mass number of an atom?
Number of protons + number of neutrons
What percentage of the atmosphere is made up of Nitrogen, and what is the chemical formula of that Nitrogen?
78% of the atmosphere is made of Nitrogen gas, which has the formula N2
Are covalent bonds or ionic bonds stronger?
Covalent bonds are stronger than ionic bonds.
Is a pH of 11 acidic, basic, or neutral?
Basic
What are the technical terms for the columns AND rows on the periodic table? (Write your answer for the columns first and for the rows second.)
Groups (columns) and periods (rows)
What is a "half-life"?
The amount of time necessary for half of the nuclei in a radioactive sample to go through nuclear decay
What form of Nitrogen can be used by plants and animals?
Nitrate (NO3)
What are the products of a combustion reaction?
H2O and CO2
Which of these is the most acidic?
Bleach
Bananas
Tomatoes
Broccoli
Tomatoes
What is special about the elements in group 18?
These are the "Noble Gases." They already have a full octet (outer shell of electrons) and therefore they do not react with other elements.
Describe what happens when an atom undergoes beta decay.
A neutron transforms into 1 proton and 1 electron. The proton stays in the nucleus and the electron is emitted (released) as a beta particle. The mass number of the atom stays the same, and the atomic number increases by 1, changing the identity of the element.
Why is Nitrogen pollution a problem? (Be specific!)
When excess nitrate from fertilizer and animal waste makes its way into waterways, it can cause an overgrowth of algae. When the algae die, they are decomposed by bacteria in the water, which use up all of the dissolved oxygen. This creates a "dead zone."
Why do chemical bonds form between atoms?
It allows them to have their electrons in a more stable configuration, typically by creating a full "outer shell" of electrons. This is also called the "octet rule."
If exactly 1 mole of hydrochloric acid is combined with 1 mole of sodium hydroxide (basic), what will the pH of the product be?
7 (neutral)
Which element on the periodic table has the LARGEST radius? (You can either say the name of the element OR show where on the periodic table you would expect to find it.)
Francium (Fr), at the lower-left corner of the table.
You have 100 grams of Minecraftium, which has a half life of 300 years. After 1200 years, how many grams of Minecraftium are left?
6.25 g
A friend is growing tomatoes in their garden. You visit and discover that they are adding antibiotics into the soil to kill bacteria. They explain that they want to make sure their food is "clean" and free from harmful bacterial contamination. Is this a good idea? Why or why not?
This is a bad idea. Without the bacteria that perform nitrogen fixation and nitrification, the plants will not be able to get the nitrogen they need to grow. They will quickly use up whatever nitrate is already present in the soil and then die unless synthetic fertilizer is added.
Why do chemical reactions always have the same number of atoms in the reactants and in the products?
Because chemical reactions cannot create or destroy matter (law of conservation of matter.) The atoms can only be rearranged.
No matter which acid and base are mixed, all acid-base reactions have 1 product in common. (They make other products as well, but there will be 1 that all acid-base reactions share.) What is this product?
Water, because H+ + OH- creates H2O.
True or false:
Elements in the same period have similar chemical bonding properties because they have the same number of valence electrons.
False!
Elements in the same period (row) have the same number of energy levels but not the same number of valence electrons.
Elements in the same group (column) have the same number of valence electrons and therefore have similar bonding properties.
What is the daughter product of uranium-235 if it goes through alpha decay?
Thorium-231
(23190 Th)