How to grow geodes crystals?

They will need to be just a touch larger than your eggshells. We loved the glass bowls because it was so much easier to watch the growth process. Carefully crack several eggs and scramble the innards for lunch. Take your shells and wash them gently under warm water.

Explanation:

Explanation:

Pour about a half cup of hot tap water into a cup.

Stir in alum until it stops dissolving. ...

Add food coloring, if desired. ...

Set your eggshell or plaster geode inside a cup or bowl. ...

Pour the alum solution into the geode, allowing it to overflow into the surrounding container and eventually cover the geode.

it takes 15 hours to complete

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.