A student lives in an apartment complex next to a park and train tracks. The student observes that they can hear the train coming sooner and from farther away when they are in front of their apartment and can only barely hear the train when they are in the park despite both being the same distance from the railroad tracks.





The student developed the model above. Using the model, identify two potential wave phenomena that occur and are the reason behind why the student can only hear the train in front of the apartment complex.



A.
The train can be heard more easily in front of the apartment complex because of reflection and interference. As the sound comes from the train, the sound waves reflect off of the complex and interfere with each other increasing the amplitude of the wave to make it easier to hear.

B.
The train can not be heard as easily in the park because of reflection and diffraction. The sound reflects off of the trees in the park and diffract between the trees, this causes the waves to bend too much to be heard.

C.
The train can be heard more easily in front of the apartment complex because of diffraction and refraction. The sound waves diffract between the other buildings aiming them towards the apartment complex and then the sound refracts through the apartment complex which makes it more difficult to hear in the park.

D.
The train can not be heard as easily in the park because of interference and reflection. The other buildings in front of the park cause interference of the sound waves from the train and the trees in the park cause reflection making it too hard to hear the train.

Answer:

In a chemical change the nature of the substance changes and it is transformed, for example when a piece of wood is burned, the carbon is being transformed into carbon dioxide. A physical change is one where the nature of matter does not vary.

I hpoe help you.

Answer:

physical changes only change the appearance of a substance not it's chemical composition .chemical changes change the substance with a new chemical formula

Explanation:

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 102 g

volume = 24.5 mL

We have

[tex]density = \frac{102}{24.5} \\ = 4.163265306...[/tex]

We have the final answer as

Hope this helps you

Answer:

Sudden decrease in the velocity at the boundary.

Explanation:

The shadow zone is the zone of the earth from angular distances of 104° to 140° from a known earthquake that does not directly receive any P waves. Now, this shadow zone occurs as a result of S waves getting stopped completely by the liquid core and the P waves being refracted by the liquid core.

From earlier seismic discoveries, this boundary which is the shadow zone that does not directly receive any P-waves was found to be due to the fact that the P-waves were refracted inwards as a result of the sudden decrease in velocity at the boundary.

Answer:

1.Mg+O2.......MgO2

Explanation:

2.Very reactive towards halogens and reacts with water at room temperature. 3, Magnesium oxide is a simple basic oxide. 4.It will react with water to form magnesium hydroxide which is a base turning red litmus to blue 5.should be white. hope it helped. I help people although when I post a question it is left unanswered and then gets answers after two days when I don't really need it

Answer:

Smallest to Largest:

Clay is smaller then 1/125 mm

Silt is 1/256- 1/16 mm

Sand is 1/16-2 mm

Pebble is 2-64 mm

Cobble is 64-256 mm

Boulder is greater then 256 mm

Explanation:

Answer:

Observation

Explanation:

In chemistry a chemist conducts an experiment and he/she concludes some points and arranges information about his/her experiment can be called observation or result

Organizing information in a meaningful way is an example of good management and the proper establishment of the research parameters.

Learn more about this topic here:

https://brainly.com/question/19171560?referrer=searchResults

Answer:

Group 8A

Explanation:

Group 8A elements are characterized by having full outermost s and p orbitals. These elements are also known as the noble gases or inert gases. They occupy the last group on the periodic table.

Some of the elements in this group are Neon, Argon, Krypton, Xenon, and Radon.

Answer:

Water is a bent molecule with bond angles of 104.5o

Water has two pairs of unbonded electrons which are spread out evenly between the hydrogen atoms

Explanation:

Water is a substance with chemical formula, H2O i.e. two hydrogen atoms bonded to one hydrogen atom. The more electronegative oxygen atom draws electron from the less electronegative hydrogen atoms to make the molecule a POLAR ONE. The water molecule assumes a bent shape with bond angle 104.5°.

The oxygen atom has two lone pairs of electrons, which each hydrogen atom is attracted to. This strong attraction forms hydrogen bonds in the water molecule. Hence, the two pairs of unbonded electrons in the water molecule are spread out evenly between the hydrogen atoms.

Answer:

C

Explanation:

It should be acidic soil that is below pH7. pH2-pH4 is too low and it is a strong acid. Plants won't survive in very high acidity soil

Answer:

atoms tend to react in order to gain 8 valence electrons

Explanation:

The octet rule describes the tendency of atoms of elements to react in order to have eight electrons in their valence shell. This is because having eight valence electrons confers stability to the atoms of these elements in the compounds they form.

The octet rule only does not apply to the transition elements or the inner transition elements as only the s and p electrons are involved. the electronic configuration in atoms having an octet is s²p⁶.

For example, sodium atom has one valence electron in its valence shell but a complete octet in the inner shell; it will react with chlorine atom which has seven valence electrons to form a stable compound, sodium chloride by donating its one valence electron in order to have an octet. Similarly, the chlorine atom will then have an octet by accepting the one electron from sodium atom.

Answer:

Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion

Explanation:

pleaseee mark brainliest <3!

Answer:

A

Explanation:

A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.

Answer:

to be honest I don't know

Explanation:

my brain won't work with this

Answer:

The attraction between two atoms that already participate in other chemical bonds is a hydrogen bond

Answer:

Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell.

Answer:

7.49 × 108

Explanation:

Scientific notation is a way to express numbers in a form that makes numbers that are too small or too large more convenient to write. It is commonly used in mathematics, engineering, and science, as it can help simplify arithmetic operations. In scientific notation, numbers are written as a base, b, referred to as the significant, multiplied by 10 raised to an integer exponent, n, which is referred to as the order of magnitude:

Answer:

false, it is the number of protons and neutrons

Explanation:

Answer:

Plastic

Explanation

Found on google

Key concepts

Physics

Chemistry

Density

Liquids

Introduction

You probably know that when solid objects are placed in liquid, they can sink or float. But did you know that liquids can also sink or float? In fact, it is possible to stack different layers of liquids on top of one another. The key is that all the different layers must have different densities. You can stack them by picking several liquids with a range of densities or by varying the density of one liquid by adding chemicals such as sugar or salt to it. If you choose colored liquids or add food coloring to each layer, you can even create a whole rainbow of colors in one single glass! Want to see for yourself? In this science activity you will stack several liquids—one by one—and create a colorful density column!

Background

Whether an object sinks or floats depends on its density compared with the density of the liquid into which it is dropped. All types of matter—solids as well as liquids—are made up of many different atoms. Depending on the mass of these atoms, their size and the way they are arranged, different substances will have different densities. The density is characteristic for each individual compound and defined as the mass of a compound divided by its volume. In other words, the more matter there is in a certain amount of volume, the denser a substance is. One cubic centimeter of rock, for example, is much heavier than a cubic centimeter of wood. This is because there is much more matter in the same volume of rock compared with the wood.

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Liquids can also have different densities. Freshwater, for example, has a density of about one gram per cubic centimeter at room temperature. Any compound—liquid or solid—that has a higher density than water will sink whereas substances with a lower density than that will float. You can test that for yourself by gathering several liquids that you have in your kitchen such as vegetable oil, corn syrup, dishwashing soap, water, rubbing alcohol and more. Which one of these do you think will sink or float in water? Find out in this activity!

Materials

Glass or cup

Water

Food coloring

Scissors

Rubber band (wide)

Small piece of wax

Popsicle stick

At least two small, clear jars or transparent mini cups (two ounces) with lids

Permanent marker

Masking tape

Three tablespoons

Dark corn syrup

Vegetable oil

Penny

Paper towels

Rubbing alcohol, dishwashing soap and other liquids (optional)

Sugar (optional)

Preparation

Gather all your materials at a workspace that can tolerate spills of all the liquids.

Fill a cup with tap water and add a couple of drops of food coloring to the water.

Ask an adult to help you cut and prepare small pieces (about 0.5 by 0.5 centimeter) of the rubber band, the popsicle stick and the wax.

Place the two empty jars in front of you (without the lids) and label them “1” and “2” with a piece of tape and the permanent marker.

Procedure

Take a clean tablespoon and pour two tablespoons of corn syrup in jar 1.

With the second tablespoon, carefully pour two tablespoons of colored water into jar 1 on top of the corn syrup. What happens to the water on top of the corn syrup? Does it mix or stay separate?

Use the third clean tablespoon to pour two tablespoons of vegetable oil in jar “1” on top of the colored water. Do you see mixing of the liquids? What happens to the oil? Does it float on top or sink to the bottom?

Now take empty jar 2 and add the same liquids—but in reverse order. Start by pouring in two tablespoons of vegetable oil.

Answer:

oxygen and magnesium come together in a chemical to form a reaction to it compound after it burns then it forms white powder of magnesium oxide but in the process magnesium gives up 2 electrons to oxygen atoms to form powdery product.

when you burn methane it crrates a blue flame in sufficient amounts of oxygen methane burns to give off carbon dioxide (Co2) and water (H2o)

Answer:

[Kr] 4d10 5s1 or 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1

Answer:

C

Explanation:

CH₄ is the formula for methane

Answer:

Can we find a safe cure for cancer?

Explanation:

pls mark brainliest

Answer:

no

Explanation:

it is not endothermic reaction

Answer:

10 electrons

Explanation:

Neon 21 has 10 protons and 11 neutrons. We know that there are the same number of electrons as there are protons. so your answer is 10.