Unit 1: Chemistry of Life Flashcards
Together, just four elements make up more than 95 percent of the body’s mass. These include:
Oxygen, carbon, hydrogen, nitrogen
The smallest unit of an element that still retains the distinctive behaviour of that element is an:
Atom
The characteristic that gives an element its distinctive properties is its number of:
Protons
On the periodic table, the number reported as the atomic mass is typically the “average atomic mass” of all naturally occurring isotopes, and considers the relative abundances of each isotope. On the periodic table of elements, mercury (Hg) has an atomic number of 80 and an atomic mass number of 200.59. Hg has seven stable isotopes. The most abundant atoms of Hg probably have:
More than 80 neutrons each
Protium, (hydrogen isotope), has a mass number of one. This means that it has:
One proton, no neutrons, and one electron
Oxygen has an atomic number of 8. How many electron shells does it likely have:
2
A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with______?
Polar covalent bonds
When a neutral atom, like sodium (Na) donates an electron to another atom, it becomes:
An ion
A substance formed of crystals of equal numbers of anions and cations held together by ionic bonds is called a(n)?
Salt
Na(+) + Cl(-) -> NaCl is an example of a(n) _________ reaction?
Synthesis
_________ reactions release energy.
Exergonic
Which of the following combinations of atoms is MOST likely to result in a chemical reaction?
Hydrogen + Helium
Hydrogen + Hydrogen
Neon + Oxygen
Helium + Oxygen
Hydrogen + Hydrogen
CH4 is methane. This compound is ________.
Organic
A liquid medication that appears homogenous at first, starts to separate after a few minutes. This type of liquid is a _________.
Suspension
Energy that is transmitted as waves, including microwaves, is which type of energy?
Radiant
Which of the following correctly orders items from lowest pH to highest?
1) hydrochloric acid, blood, ammonia
2) blood, baking soda, pure water
3) saliva, coffee, lemon juice
4) pure water, bleach, urine
1) hydrochloric acid, blood, ammonia
What is TRUE about acids?
1) It has a pH of 7 or higher
2) It accepts H(+) in a solution
3) It increases the concentration of H(+) in an aqueous solution
4) It releases OH(-) into a solution
3) It increases the concentration of H(+) in an aqueous solution
Which of the following is FALSE about blood pH?
1) It normally ranges from 7.35 to 7.45
2) In normal circumstances, it is slightly alkaline
3) It can be regulated by several means, including chemical buffer systems
4) The body can tolerate a wide range of pH
4) The body can tolerate a wide range of pH
In a dehydration reaction:
A new product is synthesized and molecule of water is released as a by product
What are Ionic Bonds?
Close association between ions of opposite charge.
Cation is +
Anion is -
What are Covalent Bonds?
They share electrons in a mutually stabilizing way.
Polar: extremes, positives and negatives
Nonpolar: not charged, no negatives or positives
What are Hydrogen bonds?
Formed when a weakly positive hydrogen atom already bonded to one electronegative atom (Oxygen in water to another electronegative atom from another molecule)
What are some examples of form of energy we use?
Kinestic, potential, gravitational, chemical, mechanical, electrical
What is a synthesis reaction?
A + B = AB
What is a decomposition reaction?
AB = A + B
What is an exchange reaction?
AB + CD = AD + BC
What factors can influence the rate of a reaction?
Surface area, reactivity, temperature, concentration, enzymes or catalysts
What are enzymes?
A control system for enzymatic activity in which enzymes are turned “on” or “off” depending on the organism’s needs; decrease the activation energy needed for a chemical reaction to occur.
