Whats the sum of the coefficients in Na2O + AIBr3 = NaBr AI2O3 of all the reactants and products when this equation is balanced?

Answer:

Answer: 12

Explanation:

[tex]{ \sf{3Na _{2} O +2 AIBr _{3} \rightarrow 6NaBr + AI _{2} O _{3} }}[/tex]

[tex]{ \tt{sum = 3 + 2 + 6 + 1}} \\ = { \tt{12}}[/tex]

Answer:

12

Explanation:

3+2+6+1

I need help quickly, this assignment is due in a few hours. I have a few 8th grade science questions I need help with. These is not need to explain your answer, just tell me if the answer is a,b, or c. Also, please answer all of the questions listed not just some of them. I will be giving 20 points if you answer, and brainly to the first person to answer. The questions look really complicated but it is mainly just a long description. The questions themselves seem simple.

QUESTION ONE : Miranda was learning to bake bread at home. Her first few batches of dough did not rise, or expand, as much as they should have. Miranda's mother noted that the kitchen was cold and suggested that the dough might not be warm enough to rise. Miranda decided to test her mother's suggestion. She made a large batch of dough and divided it into six equal-sized balls. Then, she put each ball into a bowl. She left three bowls on the counter in the kitchen, where the temperature was 63oF. She left the other three bowls on her desk in her upstairs bedroom, where the temperature was 80F. After one hour, Miranda measured the size of each dough ball.

Which of the following was the dependent variable in the experiment?
a. the temperature where the dough was left to rise
b. the ingredients used to make the dough
c. the size of each dough ball

QUESTION TWO: Jada liked to make guacamole, but she could often find only unripe avocados at the grocery store. In biology class, Jada learned that ripe fruits produce a gas called ethylene that can cause other fruits to ripen. Jada wondered whether storing ripe bananas with unripe avocados would make the avocados ripen faster. Jada prepared four paper bags with five unripe avocados in each bag. She added on ripe banana to two of the bags. Then, Jada sealed all four bags. After three days, she opened each bag and counted the number of ripe avocados in each bag.

Which of the following was the independent variable in this experiment?
a. the type of paper bag used
b. the number of bags with a ripe banana
c. the number of ripe avocados

QUESTION THREE: Colette was using steel to make rusted sculptures. After building each sculpture, she caused the steel in the sculpture to rust by placing it into tub filled with salt water for eight hours. Colette wondered if steel would rust faster submerged in vinegar instead of salt water. To find out, Colette cut ten squares of steel sheet metal and split them into two equal groups. She put one group of squares into a tub filled with salt water and the other group of squares into a tub filled with vinegar. Once an hour for eight hours, Colette counted the number of rusted steel squares in each group.

Which of the following was a variable that was held constant (control variable) in this experiment?
a. the type of liquid used
b. the size of the squares of steel sheet metal
c. the number of rusted steel squares

QUESTION FOUR: David divided 40 unripe bananas evenly among eight paper bags and sealed the bags. He poked 20 small holes in four of the bags and left the other four without holes. He kept the bags at room temperature for three days. Then, David opened the bags and counted the number of brown spots on each banana. He compared the average number of brown spots on bananas from bags with holes to the average number of brown spots on bananas from bags without holes.

Identify the question that David's experiment can best answer.
a. Do bananas develop more brown spots when they are kept at room temperature compared to in a cold refrigerator?
b. Do bananas develop more brown spots if they are kept in bags with holes compared to bags without holes?
c. Do bananas develop more brown spots when they are kept in brown paper bags compared to in a plastic bag?

QUESTION FIVE: Ten groups of chemistry students combined three solutions that, when mixed, chemically reacted and turned blue. Before mixing, five groups of students heated the solutions to 25C, and five other groups heated the solutions to 50C. The students recorded how many seconds it took for the mixtures to turn blue. Then, the groups shared their results, and the class compared the time it took for the mixtures to turn blue at 25C and at 50C.

Identify the question that the students' experiment can best answer.
a. Does the type of color the mixture produces depend on the temperature of the solutions?
b. Does the mixture of solutions release more gas when they are mixed at 25C compared to 50C?
c. Does the mixture's color change faster when the solutions are mixed at 25C or 50C?

What is an example of variation in a behavioral adaptation of an individual in a population?
A. a bird that migrates to a warmer region
B. a rabbit with brown fur
C. a cows stomach being able to digest cellulose
D. a rose that has many thorns

Which is an example of variation in a structural adaptation of an individual in a population?

A. the thickness of a bear’s fur
B. the size of a deer herd
C. the hibernation of a squirrel
D. a wren’s yearly migrations