1.
Four elements make up what percent of the human body
Correct Answer
A. 96%
Explanation
The answer is 96% because the question is asking for the percentage of the human body that is made up of four elements. Since there are no other options or information provided, we can assume that the correct answer is 96%.
2.
What are the four elements that make up so much of our body
Correct Answer
D. Nitrogen, Carbon, Oxygen and Hydrogen
Explanation
Nitrogen, carbon, oxygen, and hydrogen are the four elements that make up a significant portion of our body. Nitrogen is a vital component of proteins and nucleic acids. Carbon is the backbone of organic molecules and is involved in various biological processes. Oxygen is necessary for cellular respiration and energy production. Hydrogen is present in water and is involved in many biochemical reactions. These four elements are essential for the structure and function of biological molecules in our body.
3.
The primary element that forms the chemical basis for all known life on Earth is __________.
Correct Answer
Carbon, carbon
Explanation
Carbon is the primary element forming the chemical basis for all known life due to its unique ability to form stable bonds with many elements, including itself. This versatility allows for the creation of a vast array of complex molecules essential for life, such as carbohydrates, proteins, lipids, and nucleic acids. Carbon's bonding properties make it the backbone of organic chemistry, which is the foundation of biological processes.
4.
What is the Octet Rule?
Correct Answer
C. 2-8-8
Explanation
The Octet Rule states that atoms tend to gain, lose, or share electrons in order to achieve a full outer shell with eight electrons. This is because having a full outer shell makes atoms more stable. The correct answer, 2-8-8, represents the electron configuration of the noble gas neon (Ne), which has a full outer shell and follows the Octet Rule.
5.
Which is a subatomic particle?
Correct Answer
E. Both B and D
Explanation
Both the electron and proton are subatomic particles. The electron has a negative charge and is found outside the nucleus of an atom, while the proton has a positive charge and is located within the nucleus. Therefore, both options B and D are correct as they both represent subatomic particles.
6.
Atomic weight is the number of _____ plus nuetrons in the nucleus
Correct Answer
Protons, protons
Explanation
Atomic weight is the number of protons plus neutrons in the nucleus. The atomic weight is determined by adding up the masses of the protons and neutrons in an atom. Protons are positively charged particles found in the nucleus of an atom, and they contribute to the overall mass of the atom. Neutrons are neutral particles also found in the nucleus, and they also contribute to the mass of the atom. Therefore, the atomic weight is the sum of the number of protons and neutrons in an atom.
7.
This compound has little or no carbon to carbon bonds
Correct Answer
D. Inorganic Compound
Explanation
The correct answer is Inorganic Compound. This is because an inorganic compound is characterized by the absence or minimal presence of carbon to carbon bonds. Organic compounds, on the other hand, are primarily composed of carbon and hydrogen atoms and typically contain carbon to carbon bonds. Isotope compounds and cationic compounds do not specifically refer to the absence of carbon to carbon bonds, so they are not the correct answer.
8.
True or False: Electrons are part of the atomic weight
Correct Answer
B. False
Explanation
Electrons are not part of the atomic weight because atomic weight is determined by the combined mass of protons and neutrons in an atom's nucleus. Electrons have negligible mass compared to protons and neutrons, so they do not significantly contribute to the atomic weight. Therefore, the correct answer is False.
9.
If there are 8 protons in the nucleus of an atom how many electrons are there?
Correct Answer
A. 8
Explanation
The number of electrons in an atom is equal to the number of protons in its nucleus, as atoms are electrically neutral. Since there are 8 protons in the nucleus of the atom mentioned in the question, there must also be 8 electrons.