7th grade help me plzzzzzzzzzz

7th Grade Help Me Plzzzzzzzzzz

Answers

Answer 1
The first choice is correct
Answer 2
density is mass divided by volume

Related Questions

first to answer correctly gets brainleist! (you dont needa hear that vid thingy tahts just for ppl who cant read or need orial commidations or wtv lol)

Answers

I think the answer is c

Answer:

The seasons are a result of the tilt of the earth

A massless length of twine can withstand a maximum tension of 490 N. The twine is used to spin a 28-kg ball in horizontal circular motion of radius 1.8 m. The ball is spun faster and faster until the twine breaks. What was the maximum speed of the ball?

7.2 m/s
3.2 m/s
5.6 m/s
11 m/s

Answers

Answer:

5.6 m/s

Explanation:

Use the equation below to solve the problem that follows.

2H2 (g) + O2 (g) → 2H2O (g)

When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.

Im very loss with this question

Answers

Percent yield of water : 70%

Further explanation

Reaction

2H₂ (g) + O₂ (g) → 2H₂O (g)

mol H₂(MW= 2 g/mol) :

[tex]\tt \dfrac{13.8~g}{2~g/mol}=6.9~mol[/tex]

mol H₂O = mol H₂ = 6.9

mass H₂O(theoretical) :

[tex]\tt 6.9\times 18~g/mol=124.2~g[/tex]

[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{87}{124.2}\times 100\%=70\%[/tex]

Does the model correctly represent the electron dot diagram of magnesium? Why or why not? Check all that apply.
M g with 1 dot above and 1 right.
*{Yes, because the chemical symbol of magnesium is Mg.}
No, because the chemical symbol of magnesium is Mn.
*{Yes, because magnesium has two valence electrons.}
No, because magnesium has seven valence electrons.
No, because both of the dots should be on top of the chemical symbol

Answer 1 and 3

Answers

Answer:

1 and 3

Explanation:

Answer: A and B or 1 and 3

Explanation:

Can somebody help me with this??!

Answers

What is the question? What is it asking u to do

answer this pls thanks

Answers

Answer:  It is element nitrogen. It has an atomic number of 7 and the valence electron is 5. It needs 3 electrons to complete its octet state. That's why sometimes it has the oxidation number of -3 in ammonia.

Yeah i have no idea sorry

whats the formula for mass

Answers

Answer:

The unit of molar mass is kg/mol. Where, m = mass, v = velocity.

Hope that helps :)

Colour in acid of red litmus paper​

Answers

Red

Litmus paper turn red when it comes in contact with acid. It turn blue if it come in contact with a base. Neutral litmus paper is purple

Which of these describes a challenge that the engineer of a high-altitude
airplane would need to consider?
A. More fuel is used at higher altitudes.
B. The airplane may succumb to the power of gravity as lift
decreases at higher altitudes.
C. The airplane may need a heat shield for protection from sonic
booms.
O D. The airplane will create more drag at higher altitudes than lower
altitudes.

Answers

Answer:

I think its (B)

Explanation:

as when the air thins out at higher elevations, your lift decreases so at some point, the plane cant produce enough lift to overcome gravity.

The answer is option B.

Need help ASAP!!please

Answers

It would be option 2 because water is the most dense with 1.0 detergent is the next most dense with .93 and the oil is the least dense with .92

What is the concentration of a solution of 10. Moles of copper nitrate in 5.0 liters of solution

Answers

Answer:

10.5

Explanation:

well we added together so thats the result

Which of the following elements is a metalloid? A. phosphorus B. cobalt C. silicon D. magnesium

Answers

Answer: silicon

Explanation:it just is

Respuesta

es la C. silicio

Explanation:

No existe una definición estandarizada de elemento metaloide ni un consenso completo sobre los elementos que son metaloides.

En la clasificación de metaloides se suelen incluir a:

Boro (B)

Silicio (Si)

Germanio (Ge)

Arsénico (As)

Antimonio (Sb)

Telurio (Te)


This is methane, Methane is gas that is found in small quantities in Earth's atmosphere. Methane is the simplest hydrocarbon,
consisting of one carbon atom and a powerful greenhouse gas. What is the chemical formula for methane?
A)
4CH
B)
C4H
C)
C4H4
D)
CH4

Answers

Answer:

CH4

Explanation:

I looked it up and took the test

Answer:

You go to K12?

Explanation:

Which of the following describes the energy transformations that occur when a toaster is used to make toast?

Thermal energy is transformed into chemical energy in the toaster, and chemical energy is transformed into thermal energy in the toast.

Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast.

Light energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.

Electrical energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.

Answers

Answer:

Thermal energy (B)

Explanation:

just did it

Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.

What is chemical energy?

Chemical energy is defined as chemical substances' potential energy, which is released as they experience chemical reactions and change into other substances. Additionally, it is what binds a substance's molecule's together. The body transforms or changes the chemical energy in food into heat and mechanical motion.

The wire attached to the power source transmits electrical energy to the toaster. The heating element is a part of the toaster. This heating element transforms electrical energy into heat energy, which aids in toast preparation, when it comes into contact with it. Thus, with an electric toaster, electrical energy is converted to heat energy.

Thus, electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.

To learn more about chemical energy, refer to the link below:

https://brainly.com/question/1371184

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Why do electrons falling into different orbits give off characteristics wavelengths?​

Answers

Explanation:

Because the difference in energy between orbits is different in different types of atoms, moving electrons between different orbits requires photons carrying different amounts of energy (different wavelengths).

Help please! I’ll mark brainliest to who ever answers this first!!

Answers

Answer:

paleontologists is the answer to scientist who studies fossil

What does the symbol △ in a chemical equation mean?

Answers

Answer:

Delta, or subject to change.

Explanation:

Δ→ triangle indicates that the reaction is being heated.

What is a chemical equation?

Chemical equations are symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.

To express heating, we usually use Δ over reaction arrows like:

[tex]CaCO_ 3[/tex]. Δ → [tex]CaO+O_2.[/tex]

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What makes the element oxygen different from the element hydrogen?

Answers

Answer: the difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen this means it takes two water molecules (2 H2O) to make one oxygen molecule (02) .At the same time however two molecules of water (2 H20) can make two molecules of hydrogen (2 H20)

 

Explanation: hope this helped and mark me as brainliest please =)

8
Calcium carbonate (limestone) decomposes when heated.
Caco, + CaO + CO2

b) Calculate the volume of carbon dioxide produced if 10 grames were decomposed.​

Answers

Explanation:

Equation -

CaCO₃ → CaO + CO₂

molecular masses of -

CaCO₃ = 40+12+16×3 = 100 g/mol

CaO = 40+16 = 56 g/mol

CO₂ = 12+16×2 = 44 g/mol

Now,

If 100 g of CaCO₃ is decomposed then it produces 56 g of CaO and 44g of CO₂

Then,

If 1 g of CaCO₃ is decomposed then it produces 56/100g of CaO and 44/100g of CO₂

Now,

Here in question, 10g of CaCO₃ is decomposed

It means, It produces

56/100 × 10 = 56/10 = 5.6 g of CaO and

44/100 × 10 = 44/10 = 4.4 g of CO₂

Now,

we get that 10 g of CaCO₃ on burning produces 4.4 g of CO₂

we need to calculate volume of 4.4 g of CO₂

mole = mass/Gram molecular mass

Then,

mole = 4.4/44 = 0.1

Now,

volume = mole × 22.4 (in Litres)

= 0.1 × 22.4 = 2.24 L

Hence,

2.24 L of CO₂ will be produced when 10g of CaCO₃ decomposed.

You can see protons yes or no

Answers

No. Not with the naked eye

Someone answer these please! It’s multiple choice

Answers

Answer: Number 1 is titanium.

The one where you calculate a tin block is 13.0cm.

3. Is A) Same Density And Same Chemical Properties.

4. Is also A. Ne

Explanation:

How does a longshore current change the beach

Answers

Answer:

As this sheet of water moves on and off the beach, it can “capture” and transport beach sediment back out to sea. This process, known as “longshore drift,” can cause significant beach erosion.

Carbon dioxide is formed by the given formula.
C(s)+O2(g)→CO2(g)
Carbon dioxide is
A
a compound of two elements, carbon and oxygen.

B
a mixture of two compounds, carbon and oxygen.

C
a compound of two atoms, carbon and oxygen.

D
an element of two atoms, carbon and oxygen.

Answers

Answer:

A

Explanation:

If the temperature of a substance increases will the particles of that substance be moving faster or slower or at the same speed as they were before the temperature changed

Answers

Answer:

If the temperature increases, temperature reflects the speed of the molecules, so if the molecules are at a higher temperature, they are faster and they start to break bonds and new things react.

Explanation:

First person to comment there crush name get brainlyest

Answers

Answer:

:0

Explanation:

David <3

Jeremiah pushed Anthony with a net force of 12 N. Anthony accelerated across the hall at 0.2 m/s2. What was Anthony’s mass?

Answers

Answer:

6

Explanation:

Answer:  60 kilograms

Work Shown:

Force = Mass*Acceleration

F = ma

12 = m*0.2

12/0.2 = m

60 = m

m = 60 kilograms

What is an atomic nucleus

Answers

Answer:

The atomic nucleus is the small, dense region consisting of protons and net at the center of an atom.

Explanation:

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. ... Protons and neutrons are bound together to form a nucleus by the nuclear force.

Answer:

The atomic nucleus is the small , dense region consisting of protons and neutrons at the center of an atom .

As water is cooled, its density increases until it reaches about
A. 4°C
B. 25°C
C. O'C
D. -2°C

Answers

About 4 C to for water density until it is cooled

Who knows the answer to this please help

Answers

The number 4 try is because

An object has a mass of 441 g and a volume
of 10 cm3. What is the density of the object
in g/cm3?

Answers

The density is the ratio of the mass to the volume. The density of the object is 44.1 g/cm³.

What is density?

Density (ρ) is the quantitative measurement of the substance having grams of mass that are dissolved per cubic meter of the solution. The density is calculated as:

ρ = M ÷ V

Given,

Mass of the object = 441 gm

The volume of the object = 10 cubic meter

Density is calculated as:

ρ = 441 ÷ 10

= 44.1 g/cm³

Therefore, 44.1 g/cm³ is the density of the object.

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