A class of students is designing a carrier to help keep foods warmer during long-distance trips. The students plan to use a chemical reaction to help keep the carrier and the food warm. The students have collected temperature data over time
using four different chemical reactions, as shown in the table.
Temperature Reaction 1 Reaction 2 Reaction 3 Reaction 4
Measurement
start of
23°C
reaction
23°C 23°C 23°C
2 minutes 26°C
90°C
20°C 8°C
10 minutes 36°C 84°C 18°C 17°C
60 minutes 68°C 62°C 14°C 19°C
180 minutes 75°C 29°C 11°C 22°C
Part A
Based on the temperature data in the table, which chemical reaction should the students use for their food carrier
design?
A Reaction 1
B Reaction 2
C Reaction 3
Reaction 4

Oxidation-reduction reactions (often called "redox" for short) are reactions that involve the transfer of electrons from one species to another. oxidation states, or oxidation numbers, allow chemists to keep track of these electron transfers. in general, one element will lose electrons (oxidation), with the result that it will increase in oxidation number, and another element will gain electrons (reduction), thereby decreasing in oxidation number. the species that is oxidized is called the reducing agent or reductant. the species that is reduced is called the oxidizing agent or oxidant. to sum up: oxidation = increase in oxidation state = loss of electrons = reducing agent reduction = decrease in oxidation state = gain of electrons = oxidizing agent part a which element is oxidized in this reaction? fe2o3+3co→2fe+3co2 enter the elemental symbol. view available hint(s) is oxidized part b which element is reduced in this reaction? 2hcl+2kmno4+3h2c2o4→6co2+2mno2+2kcl+4h2o enter the elemental symbol. view available hint(s) is reduced

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

What rule is used to determine how many covalent bonds an element can form? a. the number of covalent bonds is equal to six c the number of covalent bonds is equal to five minus the group number plus the group number b. the number of covalent bonds is equal to eight d. none of the above minus the group number select the best answer from the choices provided