please help!!!!!!!!!!!!!!!!!!!!!1

Steve fills a jar with water and adds Epsom salts and ammonia. After five minutes, he observes that white particles have formed and settled at the bottom of the jar. Steve is unable to change these particles back to any of the three original substances by heating or stirring the solution. He isolates the white particles and finds that they have properties that are very different from any of the three starting materials. Which statement BEST explains Steve's observation?

Group of answer choices


A physical change occurred because no color change was observed.


A chemical change occurred because a new substance formed.


A physical change occurred because stirring did not change the solution.


A chemical change occurred because a solid substance formed.

What type of person studies and collects data on the weather?

Has negative values

Group of answer choices

Celsius and Fahrenheit

Celsius and Kelvin

Fahrenheit and Kelvin

Which point on the roller coaster's path represents the maximum (greatest) potential energy?

What would you have to do to the substance in
cup A to make the molecules behave like the ones in
cup B? Use the word "thermal energy" in your
answer.

What is NOT true about genes and chromosomes?

Genese are located on chromosomes

Chromosomes are in the nucleus

A single chromosome can contain hundreds of genes

All of these are true

Develop models bonds can be placed on a scale that ranges from 100% ionic to 100% covalent. Use what you know about the types of bonds that specific elements tend to form to place each of the following compounds in the correct location on the scale: CO2, N2 , NaF, H2O

Someone please help me if right I’ll give you 5$

What results when two waves that are completely out of phase meet?

A: constructive interference that results in a greater amplitude
B: destructive interference that results in a greater frequency
C :destructive interference that results in a lower amplitude

The image shows an example of a sedimentary rock.


Brown rock containing small pieces of different materials.


Which feature of this rock demonstrates that it is a clastic sedimentary rock?


visible crystal formations

variation of colored sediments

visible rock fragments

distribution of organic materials

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What is the charge on the Cr in Cr2O72-

What landscape feature contributes to the dryness of deserts?

A. The open, flat areas of a desert prevent clouds from forming.

B. Desert canyons collect all water and funnel it out of the desert.

C. Desert lakes absorb all the water.

D. Mountains block the winds that bring rain clouds.

Which of the following statements fully describes what an object may do when it experiences unbalanced forces? Select the two best answers.

A. It may change directions.

B. It will move at a constant speed.

C. It may slow down.

D. It may slow down or speed up.

E. It will stay stationary.

Imagine that you are a leaf on a plant, and you realize that you are running low on supplies to do your job. You decide to text the roots to set up a delivery. Write a text message conversation between the leaf and the roots that discusses and arranges this delivery.

Where is the DNA stored in a cell?

Lab: Thermal Energy Transfer

Please help, I don't get what does this means

3. Name the compound sodium makes with the following elements.
(a) Calcium carbonate: ​

Which of these phrases would go in the overlap? Select two options.

What are the four main components of a galaxy?
A. Gas, dust, rock, and planets
B. Planets, stars, gas, and rock
C. Stars, clouds, orbits, and other objects
D. Stars, gas, dust, and other objects

Match these items.

1. imprint of plant or animal
original-remains fossil
2. undecayed plant or animal part
carbonized fossil
3. replaced by a mineral
petrified fossil
4. only carbon remains
cleavage
5. mountain
geology
6. from magma
metamorphic
7. from physical and chemical changes
igneous
8. sandstone
print fossil
9. helps identify rocks
landform
10. science of Earth
sedimentary

How to work out the relative mass of potassium? What is the calculation? ( explained very easily )

Which elements do not normally form compounds?


A. nonmetals

B. alkali metals

C. metalloids

D. noble gases

What does this diagram represent?

A) a turbine
B) a motor
C) an electromagnet
D) a generator

In a reaction of yeast and hydrogen peroxide, the yeast causes a reaction in which the hydrogen peroxide breaks apart to form oxygen gas and water. Heat is released (given off) in this experiment, which would indicate a(n) ____________________ reaction.

A) equilibrium
B) endothermic
C) physical reaction
D) exothermic

Drag the tiles to the correct boxes to complete the pairs.
Match the inheritance patterns with the scenarios that exemplify them.

codominance
multiple alleles
incomplete dominance

A pink roses are formed when red roses are mated with white roses.
arrow -

Genes with the alleles IA, IB, and i are responsible
for expression of A, B, and O blood types.
arrow -

A red flower and a white flower produce
an offspring with equal proportions of red
and white coloration.
arrow -

How is the momentum of an object determined?
What happens every time one of the boys playing ping pong hits the ball?
How could the boy playing ping pong keep from hitting the ball off the table?
I GIVE 20 PTS PLS HEELP

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?

A substance that is uniform in composition, made up of two or more atoms in the same place, and NOT chemically combined is a _______________.



element

homogeneous mixture

compound

heterogeneous mixture

When the speed of the bottle is 2 m/s, the KE is kg m2/s2. When the speed of the bottle is 3 m/s, the KE is kg m2/s2. When the speed of the bottle is 4 m/s, the KE is kg m2/s2. When the speed of the bottle is 5 m/s, the KE is kg m2/s2. When the speed of the bottle is 6 m/s, the KE is kg m2/s2.
instructions
In this part of the experiment, you will be changing the speed of the bottle by dropping it from different heights. You will use the same mass, 0.250 kg, for each trial, so record this mass in Table B for each velocity. Then, calculate the expected kinetic energy (KE) at each velocity. Use the formula KE = mv2,
where m is the mass and v is the speed. Record your calculations in Table B of your Student Guide.

Where does the classification of species fall?

the second lowest

the lowest

the second highest

the highest