1. which of the following is true about phtosynthesis?
a. it is an exothermic reaction
b. it is an endothermic reaction
c. it produces carbon dioxide*
d. it occurs in animals
2. atomic theory is
a. subject to change if new information is discovered
b. a solution to the problem of differing isotopes
c. unchangeable*
d. a descriptive table that lists all of the elements
3. two nonmetals from group 16 are likely to form a
a. triple and ionic bond
b. double and ionic bond
c. triple and covalent bond
d. double and covalent bond*
4. how can you describe the location of magnesium (mg, atomic number 12) on the periodic table?
a. nonmetal
b. metalloid
c. group 2, period 3*
d. group 3, period 2
5. how many valence electrons does magnesium (mg) have?
a. 12
b. six
c. three
d. two*
6. which reaction is exothermic?
a. cellular respiration*
b. photosynthesis
c. baking soda + vinegar
d. melting ice
7. you are creating a carbon cycle poster. what could you include in the poster to demonstrate the cycling of carbon?
a. a rock falling
b. shells fossilizing
c. an eagle breathing*
d. the sun shining
8. which chemical equation is balanced?
a. H₂O > H₂+2O₂
b. 2H₂O > 2H₂+O₂*
c. 2H₂O > H₂+2O₂
d. H₂O > 2H₂+2O₂
[questions 9 & 10 have images so i'm skipping them, but i'm pretty confident about my answers for them, anyways!]
11. when two hydrogen atoms bond with one oxygen atom to form water, what happens to the electrons?
a. each hydrogen atom donates its electron to the oxygen atom
b. the oxygen atom donates an electron to each hydrogen atom
c. a pair of electrons is shared at each of the hydrogen-oxygen bonds*
d. no electrons shared or donated
12. why is frying an egg an example of a chemical change?
a. atoms are lost during the reaction as bonds are broken
b. atoms are gained during the reaction as new bonds form
c. the products have different properties than the reactants*
d. the properties of the reactants are seen in the products
13. how did the discovery of the electron change the atomic model?
a. it disproved the earlier idea of an indivisible atom*
b. it confirmed that atoms are very tiny
c. it exposed fraudulent experiments conducted by unqualified scientists
d. it proved that atoms are easier to see than once believed
14. a student analyzed two diagrams of a nitrogen atom. both diagrams showed seven protons in the nucleus, but the number of neutrons differed. what are the two nitrogen atoms?
a. electrons
b. isotopes
c. covalent bonds*
d. ionic bonds
15. what is an arrangement of all elements showing the repeating pattern of their properties?
a. atomic model
b. electron dot diagram
c. periodic table*
d. chemical formula
1. wrong, very wrong
2. wrong
6. baking soda and vinegar produce heat
14. isotopes are the same element (same number of protons) but differing number of neutrons
These were just the ones that screamed at me loudly.
thank you! would number 1 be B then?
also my answer for number 6 was right oof
1. yes B is correct. You need the sun and the whole idea is that plants use the CO2 that we produce breathing and burning fuel and convert it to wood and oxygen. CO2 + heat yields O2
I just used baking soda and vinegar to clean a shower drain last week. It is pretty exciting to watch.
1. To determine the correct answer about photosynthesis, we can analyze each option:
a. It is an exothermic reaction: We know that photosynthesis is a process where plants convert sunlight into energy, and this energy is stored in glucose molecules. Since the process involves the absorption of energy from sunlight, it is not exothermic. So, this option is incorrect.
b. It is an endothermic reaction: This option correctly describes photosynthesis. Since it requires the absorption of energy from the environment (i.e., sunlight), it is an endothermic reaction.
c. It produces carbon dioxide: Photosynthesis involves the conversion of carbon dioxide into glucose. Therefore, this option is incorrect.
d. It occurs in animals: Photosynthesis is a process that occurs in plants, algae, and some bacteria, but not in animals. Therefore, this option is incorrect.
Based on this analysis, the correct answer to question 1 is b. It is an endothermic reaction.
2. The question asks about the characteristics of atomic theory. Let's look at the given options:
a. Subject to change if new information is discovered: This option correctly describes atomic theory. Scientific theories are always subject to change when new evidence or information is discovered.
b. A solution to the problem of differing isotopes: Atomic theory is not specifically a solution to the problem of differing isotopes. It is a broader framework that explains the structure and behavior of atoms.
c. Unchangeable: This option is incorrect since scientific theories can be modified or refined based on new evidence.
d. A descriptive table that lists all of the elements: This option describes the periodic table, not atomic theory.
Therefore, the correct answer to question 2 is a. Subject to change if new information is discovered.
I hope this helps! Let me know if you have any further questions.