Question

which of the following atoms are involved in this reaction? * 2na + cl₂ → 2nacl
a. sodium and calcium
b. chlorine and oxygen
c. sodium and chlorine
d. sodium and carbon

a reaction shows 2 iron atoms reacting with 3 oxygen atoms. what is the * 10 points product?
a. feo
b. fe₂o
c. fe₂o₃
d. fe₃o₂

a student observes bubbling, a temperature change, and a color change. * 10 points what conclusion can be made?
a. a chemical reaction has occurred
b. the substance is dissolving
c. the material has melted
d. light is being absorbed

what is required to balance the following equation? * 10 points _h₂+_o₂→_h₂o
a. 1,1,1
b. 1,2,2

Explanation:

Step1: Analyze first reaction

In the reaction $2Na + Cl_2
ightarrow2NaCl$, the elements involved are sodium (Na) and chlorine (Cl).

Step2: Analyze second reaction

2 iron (Fe) atoms reacting with 3 oxygen (O) atoms gives the product with the formula $Fe_2O_3$ as we combine the atoms in the ratio they react.

Step3: Analyze third reaction

Bubbling, temperature change and color - change are signs of a chemical reaction.

Step4: Analyze fourth reaction

The balanced equation for $H_2 + O_2
ightarrow H_2O$ is $2H_2+O_2
ightarrow2H_2O$, so the coefficients are 2, 1, 2.

Answer:

1. C. Sodium and chlorine
2. C. $Fe_2O_3$
3. A. A chemical reaction has occurred
4. None of the above (the correct coefficients are 2, 1, 2)