20
very very very very very very very very hard

Answers

Answer 1
This is soooo hard! :(

Related Questions

what is geography in science​

Answers

The study of earth. Geo means earth

A hot air balloon rises because the fire warms up the air and the air circulates to fill the balloon and lift it at the same time. What type of heat transfer is this?

Answers

Answer:

convection

Explanation:

Convection is a mode of heat transfer in which the particles of a substance actually move from place to place.

During convection, warmer and less dense air rises while colder and denser air sinks downwards under gravity.

Hence; when hot air balloon rises because the fire warms up the air and the air circulates to fill the balloon and lift it at the same time, convection has taken place.

is RbCl soluble or insoluble in water

Answers

Answer:

Rubidium Chloride is an excellent water soluble crystalline Rubidium source for uses compatible with chlorides.

Compound Formula: ClRb

Melting Point: 715 °C

Boiling Point: 1,390 °C

Explanation:

A student is dissolving sugar in water to make candy. She notices that sugar lumps are forming at the bottom of the pan. What could she do to help more of the sugar dissolve?
1. Heat the solution
2. Cool the solution
3. Add more sugar to the pan
4. Take some water out the pan

Answers

1. She should heat the solution

The solutes in a solvent can be make more soluble by heating. Thus upon heating the sugar lumps forming at the bottom of the water can be easily dissolved.

What is solubility?

Solubility of substance is the fraction of its concentration which dissolves in a solvent. Solubility is affected by several factors such as temperature, pressure, molecular weight, bond type etc.

Water is known as universal solvent because, it can dissolve almost all the inorganic and organic compounds. The hydroxide ions in water forms hydrogen bonds with compounds and easily dissolve them.

By providing thermal energy the intermolecular attraction of the solute molecules can be weekend and they easily forms bonds with the solvent molecules results in dissolution. Thus option 1 is correct.

To refer more about solubility, find the link below:

https://brainly.com/question/8591226

#SPJ6

What is the job or function of cell walls in plant cellls

Answers

Answer:

The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.

Explanation:

ion

The cell walls in plant cells provide tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.
Source:Nature.com

How are molecules, compounds, and substances related?

Answers

Answer:

Molecule is the general term used to describe any atoms that are connected by chemical bonds. Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds.

Explanation:

i hope you mark me the brainliest

What is the volume of solution if 2.0 moles of 0.4 M HF are present in the solution?

Answers

Answer:

5 L

Explanation:

Molarity = mol/L   ---->    L = mol/molarity

2.0 moles / 0.4 M HF = 5 L

Pablo wants to enter the science fair. Which question could be answered through scientific investigation?

Answers

Answer:

Hello

Explanation:

utd847dcpyc08td0

what’s the question?

Which action could a student take to produce a longitudinal wave with a large amplitude

Answers

Answer:

bang on a drum

Explanation:

Answer:

Bang on drum

Explanation:

Its right.

Ultraviolet light from the Sun can

Answers

Answer:

Can cause sunburn, premature aging of the skin and damage molecules in skin cells

Explanation:

Answer:

pueden afectar directo al adn de las celulas de la piel y son causantes de las quemaduras del sol

Explanation:

Determine the volume of the product containing carbon produced when 15.0 g of C2H2 are reacted with an excess of oxygen gas

Answers

Answer:

25.8 L

Explanation:

Step 1: Write the balanced equation for the complete combustion of acetylene

C₂H₂ + 2.5 O₂ ⇒ 2 CO₂ + H₂O

Step 2: Calculate the moles corresponding to 15.0 g of C₂H₂

The molar mass of C₂H₂ is 26.04 g/mol.

15.0 g × 1 mol/26.04 g = 0.576 mol

Step 3: Calculate the moles of CO₂ produced from 0.576 moles of C₂H₂

The molar ratio of C₂H₂ to CO₂ is 1:2. The moles of CO₂ produced are 2/1 × 0.576 mol = 1.15 mol.

Step 4: Calculate the volume corresponding to 1.15 moles of CO₂

At standard temperature and pressure, 1 mole of CO₂ occupies 22.4 L.

1.15 mol × 22.4 L/1 mol = 25.8 L

Please help. I need help with all 4

Answers

Zn+CuSO4=Cu+Zn(SO4)2
Cu+CaC03=Ca+Cu2(CO3)
Na+MgCI2=NaCi+Mg
Ca+AgCI=Ag+CaCI2

definition of compounds​

Answers

a thing that is composed of two or more separate elements; a mixture.

Calculate the volume which 1.00 mole of a gas occupies at 1 atm and 298K?

Answers

Answer:

25.45 Liters

Explanation:

Using Ideal Gas Law PV = nRT => V = nRT/P

V = (1mole)(0.08206Latm/molK)(298K)/(1atm) = 25.45 Liters

3. Which of the following is the correct mathematical expression to use to
calculate the pH of a 0.10 Maqueous Ba(OH)2 solution at 25°C ?

Answers

Answer:

The pH of a 0.10 Maqueous Ba(OH)2 solution at 25°C is 13.30

Explanation:

The balanced equation is Ba(OH)2(s)→Ba2++2OH−

This indicates that the concentration is 0.2 M

We will find H+ ion concentration

As we know that

[H+][OH−]=1.0×10−14M

Given -  

[OH−]=2.0×10−1M

Putting value of [OH-] in above equation we get -  

[H+]=5.0×10−14M

pH=−log10[H+]

pH=−log10[5.0×10−14] = 13.30.

Please help me out



IF YOU POST AN INNCORRECT AWNSER OR A LINK OR RANDOME THINGS I WILL REPORT U OR BAN U .

Answers

Answer:

sorry I had never done this before

If a lab requires you to use 1.25 mol oxygen gas in a chemical reaction, how many molecules of oxygen will you need?

Answers

Answer:

7.53*10²³ molecules of oxygen will you need.

Explanation:

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

You can then apply the following rule of three: if by definition of Avogadro's Number 1 mole of oxygen gas contains 6.023*10²³ molecules, 1.25 moles contains how many molecules?

[tex]amount of molecules=\frac{1.25 moles*6.023*10^{23}molecules }{1 mole}[/tex]

amount of molecules= 7.53*10²³

7.53*10²³ molecules of oxygen will you need.

please help me do it dont worry the answers are their just put them in theright place

Answers

1. Indicator
2. Base
3. Acid
4. Hydronium ion
5. pH

A scientist suggests putting solar panels on homes to supply energy because it is usually sunny there. The amount of sun is BEST described as characteristic of which property of the area?

A. Weather
B. Climate
C. Food webs
D. Gravity

Answers

Answer:

the answer is a because if u have good wheather the panels will for no matter what

Researchers are confident that they can boost suberin production by this many times? This is for science btw

Answers

Nkm lkn k jen k ren. Jen

The molar mass of element X is 42.3 grams per mol and the molar mass for
element Y is Y 96.7 grams per mol. What is the empirical formula for a substance
containing a mass composition of 52.2% X and the remainder Y?

Answers

Answer:

X5Y2

Explanation:

% composition of X = 52.2%

% composition of Y = (100 - 52.2) = 47.8%

This means that there are 52.2g of X and 47.8g of Y in the compound

To calculate the empirical formula of the compound, we first convert the gram value to mole value by dividing by their molar masses.

X = 52.2g/42.3g/mol = 1.234mol

Y = 47.8g/96.7g/mol = 0.494mol

Next, we divide each mole value by the smallest value (0.494mol)

X = 1.234mol ÷ 0.494mol = 2.49

Y = 0.494mol ÷ 0.494mol = 1

We multiply each value by 2

X = 2.49 × 2 = 4.98

Y = 1 × 2 = 2

The simple ratio of X:Y is 5:2, hence, their empirical formula is X5Y2.

Infer why the sauce on a hot pizza burns your
mouth but the crust of the pizza does not burn
your mouth.

Answers

The cheese having a higher thermal conductivity conducts heat better so it can deliver the heat to your mouth more quickly while the pizza crust transmits heat more slowly. So, even if they were the same temperature, the cheese would more likely give your tongue/mouth a severe burn.

What is the difference between an exoplanet and a pulsar

Answers

Answer:

exoplanet: a planet that orbits a star outside the solar system.

pulsar: a celestial source of pulsating electromagnetic radiation (such as radio waves)

Explanation:

exoplanet: a planet that orbits a star outside the solar system.

pulsar: a celestial source of pulsating electromagnetic radiation (such as radio waves)

Construct an explanation for why the physical properties of the inner core, outer core, and lower mantle are essential for the development of Earth's magnetic field.

Answers

Answer:

The hot temperature of inner core and outer core is responsible for the production of magnetic field.

Explanation:

The physical properties of the inner core, outer core, and lower mantle are essential for the development of Earth's magnetic field because the very high temperature of inner core is responsible for the formation of magnetic field. If the inner core is not very hot so the magnetic field will not be generated and our earth's atmosphere will not be save from the solar wind. It can be blown away by the solar wind if this magnetic field is not present so we can conclude that the physical properties of inner core and outer core is important for the production of magnetic field.

Which situation has given to a trait that could be passed on to offspring ?

Answers

Answer:

Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents.

Explanation:

Plss markk me Brainlyist

What are cilia?

smooth covering
hair like structures
a tail
all of the above

Answers

Hair like structures... don’t click the link!

29 mols of na2So4 is how many grams

Answers

Answer:

[tex]4118\ g[/tex]

Explanation:

[tex]We\ are\ given,\\No.\ of\ moles\ of\ Na_2SO_4\ provided=29\ moles\\Hence,\\Now,\\Lets\ calculate\ the\ Gram\ Molecular\ Mass\ of\ Na_2SO_4.\\We\ know\ that,\\Gram\ Atomic\ Mass\ of\ Sodium(Na) \approx 23\ g\\Gram\ Atomic\ Mass\ of\ Sulphur(S) \approx 32\ g\\Gram\ Atomic\ Mass\ of\ Oxygen(O) \approx 16\ g\\Hence,\\We\ observe\ that,\\One\ molecule\ of\ Na_2SO_4\ is\ made\ up\ of\ 2\ Sodium\ Atoms,\ 1\\ Sulphur\ Atom\ and\ 4\ Oxygen\ Atoms.[/tex]

[tex]Hence,\\Gram\ Molecular\ Mass\ of\ Na_2SO_4=2*(GAM\ of\ Na)+1*(GAM\ of\ S)\\+4*(GAM\ of\ O)\\=2*23+1*32+4*16\\=46+32+64\\=46+96\\=142\ g[/tex]

[tex]Hence,\\We\ also\ know\ that,\\Mass\ of\ A\ Sample=No.\ of\ moles*Gram\ Molecular\ Mass\\Hence,\\Mass\ of\ 29\ moles\ of\ Na_2SO_4=29*142=4118\ g[/tex]

Answer:

4118.2

Explanation:

Given: 29 moles of na²[tex]So^{4}[/tex]

To find: In grams.

Solution: Wrong

If 1 na²[tex]So^{4}[/tex] is 142 grams, then 29 grams will be found if a set of fraction has been set up;

Let [tex]"x"[/tex] be the variable

[tex]\frac{142}{1} = \frac{29}{x}[/tex]

Cross multiply

[tex]\frac{142}{29}[/tex] [tex]= 4.9[/tex]

Correct Solution

Multiply 29 by 142 = 4118

Which body system includes the brain, spinal cord and nerves? A Circulatory B Reproductive C Nervous

Answers

Answer:

C. Nervous

Explanation:

The nervous system is a system of the body of living organisms which includes the brain, spinal cord and nerves.

How many grams are in 1.46 mol K2O?

Answers

Answer:

94.196 grams

Explanation:

Answer:

94.196 grams

Explanation:

Which geologic features help scientists determine the relative ages of rocks by their positions? Select three options.


magma

erosion

intrusions

index fossils

cross-cutting relationships

helppp i need it nowwwww

Answers

Answer:

Option D, Index fossil helps scientists to determine the relative ages of rocks by their positions

Explanation:

Index fossils are arranged in layer in such a way that the lowest layer represent the oldest fossil and the top most layer represents the youngest fossil. Scientist use this concept to determine the relative age of the rocks based on their position beneath the earth’s surface

Hence, option D is correct

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