7th grade help me plzzzzzzzz

Answer:

yes the cell membranes are semi permeable

Answer: is C&A

Explanation:the electric motor converts  electricity in to mechanical energy

the  electric generator converts mechanical energy to electricity so it could not be D.

and they don't use batteries as their main source of power so it could not be B.

hence forth it is C&A

HOPE THIS HELPS!!!!!!1

PLEASE MARK BRAINLIEST!!

Answer:

The nucleus is a collection of particles called protons, which are positively charged, and neutrons, which are electrically neutral.

Explanation:

Answer:

the person above me is right

hope you do good on your test

Explanation:

Answer: C

Explanation:

Answer:

I searched the answer up on Brainly so its not my credit.

Explanation:

The answers D.

"If you have learned that metal + nonmetal ⟶ ionic bond, the answer is D, because N and C are the only pair of nonmetals.

However, if you have learned that a bond is ionic if the electronegativity difference (ΔEN) between the two atoms is greater than 0.7, the answer is A, B, and D.

The Li-Cl bond is definitely ionic.

For Na and C, ΔEN =1.62, so the Na-C bond is a highly polar covalent bond.

For Mg and C, ΔEN = 1.24, so the Mg-C bond is a polar covalent."

Hope this helps :D

Answer:

millions of years sometimes even hundred of millions of years

Answer:

How long does it take for new fossil fuels to be created?

Explanation: so it takes 65 million years to creat new fossil fuels so i think it may be  A.millions of years i am sorry if i am wrong but i do beleave i am right

Answer:

NaOH(aq)

Explanation:

NaOH(aq) is known to precipitate Mn^2+ ions according to the following reaction; Mn^2+(aq)+2OH^−(aq)↽−−⇀Mn(OH)2(s)

Hence, manganese(II) oxide reacts more readily with NaOH(aq) under ordinary conditions precipitating the metal hydroxide solid. This is one of the characteristic reactions of Mn^2+.

Answer:

N, P, As, Sb

Explanation:

Elements present in the same group having same number of valence electrons. The first option is correct from given options because nitrogen, phosphorus, arsenic and antimony are present in same group thus having same number of electrons in outer most  energy level.

Electronic configuration of N:

N₇: [He] 2s² 2p³

Electronic configuration of P:

P₁₅: [Ne] 3s² 3p³

Electronic configuration As:

As₃₃: [Ar] 3d¹⁰ 4s² 4p³

Electronic configuration Sb:

Sb₅₁: [Kr] 4d¹⁰ 5s² 5p³

Here it is clear from electronic configuration all these elements have five number of valence electrons.

Answer:

ethanol

Explanation:

Methanol has a boiling point of 65°C, propan-1-ol has a boiling point of 97°C and ethanol has a boiling point of 87°C

Fractional distillation is used for separating miscible liquids through the use of the different vapor pressure properties of the liquids. As the mixture is heated up, components start to vaporize according to their boiling points. The component with the least boiling point vaporizes first while the component with the highest boiling point vaporizes last.

This means that methanol would vaporize at the first fraction because it has the lowest boiling point followed by ethanol at the second fraction and then propan-1-ol at the last fraction.

Answer:

What the heck is "K" but I beleive 75 is the answer, but maybe wait for sumone else to answer.

Explanation:

Answer:

30 C

Explanation:

Answer

Au2s

please mark me as brainlist

Answer:

If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. ... As the sinking plate moves deeper into the mantle, fluids are released from the rock causing the overlying mantle to partially melt.

Answer:

It is b

Explanation:

Your answer is B Particle motion is coming to a complete stop.That's your answer!

Hope this helps!!!

Answer:

B

Explanation:

i have the same test

Taking into account the Gay-Lussac's Law, the pressure will increase by a factor less than three.

Gay-Lussac's law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions against the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.

In summary, when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases.

Mathematically, Gay-Lussac's law indicates that the ratio of pressure to temperature is constant:

[tex]\frac{P}{T} =k[/tex]

Studying two different states, an initial state 1 and a final state 2, it is satisfied:

[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]

In this case, a given mass of gas in a rigid container is heated from 100 ° C to 300 ° C, that is, it is heated from 373 ° K to 573 ° K. This indicates that the temperature is increasing by a factor less than three. Since pressure is directly proportional to temperature, pressure must increase in the same proportion.

Finally, the pressure will increase by a factor less than three.

Learn more:

Answer:

c

Explanation:

its c

Earth contains a spinning electric filed. The spinning of earth core creates its magnetic field. Thus, option D is correct.

A body which rotates in its own axis is called a spinning body. Earth rotates about its along with revolving around sun.  The outer core of earth generates electric current. This is called telluric current.

Flow of this current creates an electric current which is parallels to the surface of earth. The direction of magnetic field lines will be perpendicular to the direction of current. But it comes stronger when parallel to current.

A rotating electric current results in the generation of a magnetic field. Thus spinning of  earth core generates a magnetic field and therefore, option D is correct.

To learn more about magnetic field, refer the link below:

https://brainly.com/question/11514007

#SPJ2

Explanation:

Load=500N

Effort=100N

Now,

We have,

Mechanical advantage= Load / effort

= 500/100

=5

Therefore, mechanical advantage is 5.

Answer:

Azucar, bicarbonato de sodio, lavandina, vinagre, amoniaco.

Explanation:

Podemos numerar estos compuestos

Azucar → Sacarosa → C₁₂H₂₂O₁₁

Lavandina → Hipoclorito de sodio → NaClO

Vinagre → Ácido acético → CH₃COOH

Bicarbonato de sodio → NaHCO₃

Amoníaco → NH₃

Answer:

C

Explanation:

A year is a complete revolution around the Earth

Answer:

D. Ionic

Explanation:

It has ionic bonding! Good luck ^^

Answer:

a. Reactants: F₂ and HCl molecules

Products: Cl₂ and HF

b. 4HCl + 2F₂ ----> 4HF + 2Cl₂

c. Single replacement reaction

Note: The question is not complete. The complete question is found below as well as in the attachment.

Suppose that green spheres represent chlorine atoms, yellow-green spheres represent fluorine atoms, white spheres represent hydrogen atoms, and all the molecules are gases:

a. write a formula for each of the reactants

b. write a balanced equation for the reaction

c. indicate the type of reaction as combination,decomposition, single replacement, double replacement, or combustion

Explanation:

a. From the models shown in the diagram, The reactants are F₂, HCl while the products are Cl₂ and HF respectively

b. Equation for the reaction is given below;

4HCl + 2F₂ ----> 4HF + 2Cl₂

c. The reaction is single replacement reaction such that fluorine gas molecules replace the chlorine atoms in hydrogen chloride to form hydrogen fluoride with the liberation of chlorine atoms as gaseous molecules.

Answer:

Melting

Explanation:

Could not have been erosion because erosion happens on the surface.

Could not have been weathering because weathering happens on the surface.

So we only have Cementing and Melting left....

The answer is melting, I got 100% on my test.

Hope this helps!!!! :D

Please give brainliest!!!

Answer:

D

Explanation:

In the rock cycle, surface events takes place at the surface of earth. Thus,

weathering and erosion are surface events, while the subsurface events he take place in the deeper section of the earth . Examples of sub surface events are plate tectonics and mountain building or anything that takes place in the inner core of earth.

Answer:

Earths rotation

Explanation:

Answer:

because if there was not four diferent season we would not have a day or a night because we would not be moving

Explanation:

Answer:

31,536,000 seconds

Explanation:

off google

Answer:

3.15 x 10^7s

Explanation:

Answer:

B. +5

Explanation:

Answer:

Here is the definition: A medical thermometer (also called clinical thermometer) is used for measuring human or animal body temperature.

Answer:

7m/s

Explanation:

Is the acceleration of the helicopter