SCIENCE!! i need help on the question in the middle please!!!

Where does the force come from when a bumper car changes speed?

Obi is trying to determine if a powdery, solid substance is an element or a compound. After recording some observations, he strongly heats a sample of the solid over a burner flame. After fifteen minutes, he turns off the flame and allows the sample to cool. He records his final observations in the data table.

A 3-column table with 3 rows. The first column labeled observation has entries appearance, mass (g), chemical reaction with weak acid. The second column labeled original sample has entries white solid, 100.0, bubbles. The third column labeled sample after heating has entries white solid, 56.0, no bubbles.
Which is the best explanation of his results?

A. The heating changed some of the sample to gas, causing the mass to decrease without breaking down the sample. Therefore, the original sample is a compound.

B. The appearance stayed the same, showing that the sample was not broken down by heating. Therefore, the original substance is an element.

C. The mass decreased during heating and some of the impurities escaped. Therefore, the original substance is an element.

D. The chemical reaction with acid changed, showing that the sample was broken down by heating. Therefore, the original substance is a compound.

Now, demonstrate a net force of 300 N to the right. How many ways can you do it?

A student combined equal amounts of two solutions. One solution had a pH of 2 and the other had a pH of 12. Which would most likely be the resulting pH? 1 3 6 11

As the toy car rolls away, it slows down. Why?

Which description of salt is a physical property?
A. No combustion
B. Makes ionic bonds
C. Product of mixing acids and bases
D. Solid does not conduct electricity

WILL GIVE BRAINLIEST
List three examples of where potential energy is transformed to kinetic energy in the Rube Goldberg Machine simulation. Fully explain the energy transformations using complete sentences. (Example: The ball has potential energy when it sits on the shelf that transforms to kinetic energy when it falls to the ground.)

DO NOT COPY AND PAST THE ANSWER FROM 2018 AND IF YOU HAVE A QUSTOIN ABOUT IT ASK UNDER THE QUSTION DO NOT ANSWER IT TO ASK A QUSTION

The woman riding the bike applies a force by pedaling the bike. However, she moves at a constant velocity. So her force must be balanced by another force. What force acts to balance her forward force?

Which two models would be most useful in predicting weather?
A. A mathematical model based on data
B. A plastic model of a cloud
C. A map that shows wind patterns
D. A peach used to represent Earth

What is the formula name!!
I will give brainliest !!…

How were the novae on Venus similar to the landforms in Gerya’s computer model?

Which equation using element symbols correctly describes the reaction: "One molecule of methane plus two molecules of diatomic oxygen react to form two molecules of water and one molecule of carbon dioxide?"

A group of people take a diet pill. After 3 months, they measure the amount of weight they lost.
A :Independent Variable:
B: Dependent Variable:

Which statement correctly describes the location and charge of a proton in an atom? A. The protons are inside the nucleus with a negative charge. B. The protons are inside the nucleus with a positive charge C. The protons are outside the nucleus with a negative charge. D. The protons are outside the nucleus with a positive charge.

Which subatomic particles change the mass number? (select all that apply) Protons Neutrons Electrons

What is the chemical symbol for table salt?

Which statement is true about the model of the atom below? * 20 points Captionless Image A. Positively charged particles are found outside the center of the atom. B. Negatively and positively charged particles are found in the center of the atom. C. Neutral and positively charged particles are found in the center of the atom. D. Neutral particles are found outside the center of the atom.

235
92
U +
1
0
n →
90
36
Kr +
A
56
Ba + 3
1
0
n

What element is this? Ignore my answer choice.

What causes objects to move or stay still?
Claim

Reasoning:

Evidence:

In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford made a discovery that led to the understanding that an atom consists mostly of empty space with- * 20 points A. protons orbiting a dense nucleus made of electrons and neutrons B. Neutrons and protons orbiting a cloud of electrons C. Electrons and protons orbiting a cloud of neutrons D. Electrons orbiting a dense nucleus made of protons and neutrons

The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 32ºC?
A. 64
B. 65.5
C. 65
D. 66

2. When the child is pushed in the toy car, he increases speed. Does he accelerate as he is being pushed?

Which statement best describes properties of elements? A) All elements have a similar structure and hardness. B) All elements are either metals or gases. C) All elements are solid and magnetic. D) All elements have mass and occupy space

I need help ASAP! 10 points!

Which statement best describes what a circle graph shows?
A. A frequency distribution
B. Data as proportions of a whole
C. The average of a data set
D. The relationship between two variables

Two students make a model of a tree house they want to build. The sale is 1:44. In the scale model, the tree house has 2 windows. How many windows should be the real tree house have?
A. 22
B. 88
C. 4
D. 2

CO2(g) + NH3(g) + H2O(l) → NH4HCO3(s) witch type of reaction plzz within 1 hour

You are looking at two samples of iron. One sample is very small and came from the red soil on the planet Mars. The other sample is very large and came from Earth's core. True or False, these two samples contain different atoms

Please help me identify the element. The picture is blurry so..