some students observe four different lab investigations. The students record their observations in a table.
Investigation
Observations
1
A beaker of water is
heated on a hot plate. Bubbles form in
the water, and steam is given off.
2
Oil is added to a beaker of water. Oil forms a layer on top
of the water
3
Sand and iron filings are mixed in a beaker. A magnet is
then used to separate the iron filings from the sand.
4
A piece of chalk is placed in a beaker of vinegar Bubbles
form as a gas is given off.
Which investigation most likely involved a chemical reaction?

Answer:

Number 4 is an example of a chemical reaction

Explanation:

heThe chalk is reacting with the vingear which is creating a new substance. The new substance is the gas that the reaction gives off.

√225/√25 = ?? hurry please I'm stuck on it​

will give branliest




How could you possibly see the world in slow-motion

Describe the concentration of hydronium ions and hydroxide ions when a base is added slowly to a white vinegar solution. The pH of white vinegar is 3.1.

Given the following equation: Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)

If you start with 4.50 grams of Magnesium (Mg), how many grams of Hydrogen gas (H2) will you theoretically produce? If you actually produce 0.25 grams, what is your percent yield?

please help

Help me with an easy question worth 25 points

What makes a material dense if we are calculating the Speed of light in thousand miles per second.

Solar: converts mechanical energy of _____________ into electricity.
Wind
The Sun
Water

How does resource extraction affect local and national economies?

×!¡! Measurement !¡!×
Record the volume of the liquid in the graduated cylinder.
The volume of the liquid is ______ milliliters.

1. What is the geologic time scale? Explain how the geologic time scale is a model.
2. How many millions of years was the Paleozoic?
3. During what era did the dinosaurs live?
4. During what period where the first early human relatives found?

Ill give brainliest and a 5 star review for the best answer Do you think your town or neighborhood has an ecosystem? If you don’t think so, explain why not. If you do think so, what are the producers, consumers, and decomposers in the ecosystem? What roles do humans play in this ecosystem?

Mr. Rogers wanted to study the affect of different types of music would have on students ability to complete the IA. What is his dependent variable? What Is his independent variable ?

A. classrooms
B. types of music
C. IA scores
D. students

Help please! Its due in a few minutes!!

Ill give brainliest and a 5 star review for the best answer Do you think your town or neighborhood has an ecosystem? If you don’t think so, explain why not. If you do think so, what are the producers, consumers, and decomposers in the ecosystem? What roles do humans play in this ecosystem?

Which of the following is NOT a way of making heat?
A. turning on an electric light
B. eating a sandwich
C. rubbing sticks together
D. melting an ice cube

( 15 points to whoever replies quickest no links pls ) a farmer has used a fertiliser containing ammonium nitrate, potassium nitrate and ammonium sulphate on his fields but some may have leached into a nearby river. If a sample of river water was tested, what colour would the flame be if there was fertiliser contamination

Helppppp please and I will give you a Brainliest

Does an acidic solution contain hydroxide ions? Explain your answer.

Describe the concentration of hydronium ions and hydroxide ions when a base is added slowly to a white vinegar solution. The pH of white vinegar is 3.1. Explain

WARNING (It's actually 8th grade science but it's not on here...)

The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed below. Which of these elements is in this group?

Characteristics of a group of elements
•It's shiny
•It's a solid at room temperature
• It has atoms with 2 valence electrons

Answer Choices
A. Lithium
B. Strontium
C. Aluminum
D. Silicon

A disease caused by the inflammation of mucus membranes inside the bronchial tubes. There are more than 3 million U.S. cases a year.

O 9 ? A B с The models above show particle arrangement. The following statements compare and contrast the models. 1. The substance in diagram A has the highest density. 2. The substance in diagram A has the highest energy. 3. The substances in diagrams B and C would flow freely. 4. The substance in diagram C has the lowest temperature. 5. The substances must undergo a chemical change to transform into a different model.​

HURRY PLEASE

What forces act upon a maglev train? Select the THREE (3) that apply.

air resistance
air resistance

friction with the ground/track
friction with the ground/track

magnetic fields that attract and repel
magnetic fields that attract and repel

gravity
gravity

applied forces from other vehicles

Tell me why in Louisiana it always gotta freaking have a hurricane

Explain why there would be many more plants in an ecosystem than ape-x consumers. I NEED THIS PLS

1. Land-dwelling creatures depend on the the water cycle to ___________ fresh water from its salt solution in the Earth's oceans to the atmosphere.
2. They also depend on the water cycle to ______________ water from the atmosphere down to the Earth's land.

Word Blank Bank:
Evaporate
Precipitate
Condensate
Infiltrate

why did Mendel become decide to become a teacher?

ecosystems!!!!!!!! 3 questions PLEASE ANSWER I NEED THEM BY FRIDAY


1. What would happen if there were no abiotic factors in an ecosystem?

Plants would be unable to grow and produce oxygen for the animals.

Animals would grow and flourish.

The ecosystem would get too much rain.

2.Bacteria would become the consumer instead of the decomposer.
Which of the following correctly shows the cycle of biotic factors in an ecosystem?

A. Bacteria produce food and oxygen; animals eat the plants, breathe the oxygen, and produce carbon dioxide; and plants break down dead animals and produce minerals.


B. Plants produce food and oxygen; bacteria eat the plants, breathe the oxygen, and produce carbon dioxide; and animals break down dead plants and produce minerals that help plants grow.


C. Plants produce food and oxygen; animals eat the plants, breathe the oxygen, and produce carbon dioxide; and bacteria break down dead plants and animals and produce minerals that help plants grow.


D. Animals produce food and oxygen; bacteria eat the plants, breathe the oxygen, and produce carbon dioxide; and plants break down dead animals and produce minerals.

3. the pictures

What drives the movement of Earth's tectonic plates?
A the movement of air currents pushing on the plates
OB. the convection of magma under the plates pulling them
Cthe movement of Earth on its axis pulling on the plates
Dthe convection of ocean currents above the plates pushing them

What determines a single inherited trait of an indiviual ?
a. one pair of many pairs of genes
b. a disrupted cell cycle
c. one half of the replicated DNA stand
d. amino acids joined to form proteins

ANSWER ALL OF THEM NOT PICKING

a. You have a 10 volt parallel circuit, with 2 resistors on it. What is the voltage across the first resistor? Across the second?


b. You have the same two resistors on a 10 volt series circuit. Will the voltage going into the second resistor be more, less, or the same as that going into the first resistor? Exact numbers aren’t needed!


c. You have a series circuit with a current of 6 amps and three resistors on it, with resistances of 10 ohms, 5 ohms, and 6 ohms, respectively. What is the voltage of this circuit? Show your calculation.