2. How have observations of the natural world helped
in the development of calendars?

Answers

Answer 1

Answer:

just wanted points

Explanation:

i wasted your time srry


Related Questions

Laboratory equipment is cleaned and properly stored after use primarily so that -- chemical products can be measured and recorded as data chemical products can be measured and recorded as data time is saved in setting up the next experiment time is saved in setting up the next experiment toxic materials can be kept in the laboratory toxic materials can be kept in the laboratory the possibility of contamination in the laboratory is minimized

Answers

Answer:

the possibility of contamination in the laboratory is minimized

Explanation:

When a particular laboratory equipment is used for a given purpose, it can not be used four another purpose until it has been thoroughly washed. This is done in order to avoid contamination when the equipment is subsequently used for a different purpose.

Hence, if a laboratory equipment is not properly cleaned and stored after use, they remain contaminated and give inaccurate results when subsequently used.

Which environmental impact is associated with the use of nuclear power plants?.

Answers

Answer:

A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years.

Which physical property is most helpful for separating a mixture of salt dissolved in water?
A Particle density

B Boiling point

C Rate of solution

D Magnetic attraction

Answers

Answer:

B. Boiling Point

Explanation:

To separate salt from water, you need to boil it until all the water evaporates, and you will be left with salt.

Answer:

The answer is Boiling point

Explanation:

I got it right on my exam

1. Heat and pressure deep beneath Earth's surface can change any rock into
chemical rock
gemstone
metamorphic rock
sedimentary rock

Answers

Metamorphic rock. This is because when heat is projected onto these rocks, they morph into different metamorphic rocks.

Why is the boiling point of 2 M NaCl solution higher than the boiling point of 1 M of NaCI solution?

Answers

Answer:

The fist option is correct

Explanation:

2 molecules of water have relatively large intermolecular force than a single molecule

Why don't objects warm up at equal speeds/rates?

Answers

Objects heat up and cool down at the same speed, but only when the heat exchange mechanism for cooling is the same as the mechanism for heating.

Which reaction displays an example of an arrhenius base? naoh(s) right arrow. na (aq) oh–(aq) hcl(g) h2o(l) right arrow. h3o (aq) cl–(aq) ch3cooh(aq) h2o(l) right arrow. h3o (aq) ch3coo–(aq) nh3(aq) hc2h3o2(aq) right arrow. nh4 (aq) c2h3o2–(aq)

Answers

The reaction which displays an example of an arrhenius base is

NaOH(s) → Na⁺(aq) + OH⁻(aq).

What is Arrhenius base?

According to the Arrhenius theory, those substance which gives H⁺ ion to the aqueous solution is acid and which gives OH⁻ ion to the aqueous solution is known as base.

All given chemical reactions will display an arrhenius acid, but only one reaction display as a arrhenius base as they gives OH⁻ ion to the aqueous solution and that reaction will be:
NaOH(s) → Na⁺(aq) + OH⁻(aq)

Hence option (1) is correct.

To know more about arrhenius base, visit the below link:
https://brainly.com/question/1321386

Answer:

A: NaOH(s) ---> Na+(aq) + OH–(aq)

Explanation:

Determine the wavelength, in meters, of a wave that has a frequency of 1.25 x 1020 Hz.

And what type of wave/ray is it?

Answers

Answer:

Frequency of wave is given 1.25 × 10² Hz

We have been asked to determine the wavelength of that wave ( in metres) .

We Know the speed of light in air/vacuum is

c = 3 × 10 m/s

❍[tex]\\{\underline{\boxed{\green{\bf{f = \dfrac{c}{ \lambda} }}}}}[/tex]

Put the value we obtain

[tex]\sf \implies \: 1.25 \times {10}^{20} = \dfrac{3 \times {10}^{8} }{ \lambda} \\ \\ \sf \implies \lambda \: = \dfrac{3 \times {10}^{8} }{1.25 \times {10}^{20} } \\ \\ \sf \implies \lambda = \dfrac{3}{1.25 \times {10}^{12} } \\ \\ \sf\implies \lambda = 2.4 \times {10}^{ - 12} m [/tex]

So, the wavelength of the wave is 2.4 × 10¹² m

It would be Gamma Ray .

Which deduction about the element astatine can be made from its position in group 7

Answers

It forms covalent compounds with sodium.


what section do the nonmetals fill in the quantum mechanical model of the atom?

Answers

Answer:

Section P

Explanation:

Which of these is an example of force?

a. Watching a slice of bread in the toaster

b. Pulling a casserole out of the oven

c. Listening to your school chorus

d. Taste testing soup cooking on the stovetop

Answers

Answer:B

Explanation:

B because it takes force to Pull the casserole out of the oven. The other ones do not have force and you would know that by keywords such as watching, listening, and taste

Plz help! I don't want internet answers plz :D

1. What determines weight?

2. What does Homogeneous mean?

Answers

Answer:

Explanation:

number 2 = A mixture that cannot be easily distinguished between the different parts. Distillation is one of the only ways to remove the parts from each other. For example, in a fruit salad you can easily pick things out, but in jello you cannot take the sugar out.

please give me brainilest

number 1. = The density of the bone structure and weight are essentially determined in order to determine the person's bone structure. The bone density measurement involves the size of the wrist. Determining the body frame allows an individual to estimate the best weight.  

1. Weight is determined by mass and gravity

PLEASEE HELPPP MEEEEE
Calculate the mass of 3.7 L of CH4 at STP.

Answers

Answer:

Explanation:

Molar mass CH4 = 16g/molAt STP , 16g CH4 has volume = 22.4LMass of 3.136 L CH4 = 3.136L/22.4L * 16g = 2.24g

According to the standard temperature and pressure conditions and ideal gas equation, the mass of 3.7 L of CH₄ is 0.026 g.

What are standard temperature and pressure conditions?

Standard temperature and pressure are defined as a standard set of conditions required for experimental measurements which are established to allow comparison between different sets of data.

Standards which are commonly used are those International Union of pure and applied chemistry and national institute of standards and technology.These are not universally accepted standards but are the ones which are commonly used.

Standard conditions of pressure and temperature are necessary to define standard reference conditions used to express volumes of liquids and gases.These values are important to physicists, chemists ,engineers ,pilots and navigators.

According to ideal gas equation mass= PV×molar mass/RT on substitution mass= 1×3.7×16/8.314×273=0.026 g.

Learn more about standard temperature and pressure,here:

https://brainly.com/question/29129606

#SPJ7

Assuming no other changes in temperature or volume, what will be the effect on the pressure inside a container of gas if the identity of gas is changed from nitrogen to helium

Answers

The pressure will increase if the gas is changed from nitrogen to helium.

Kinetic theory of gases

The question is incomplete but I will try to help the much I can. We must note that the kinetic energy of the molecules of a gas depends on the temperature and the molar mass of the gas.

Since the average velocity of a gas depends on molar mass also, the pressure will increase if the gas is changed from nitrogen to helium.

Learn more about gases: https://brainly.com/question/1369730

i need help again...

Answers

The theory of evolution
the theory of evolution

Using the line spectra below and information from the previous activity, determine which subatomic particles play the biggest role in determining the color of an atom

Sample 1 (Li-1-10):


Sample 2 (C-13):


Sample 3 (C+2-18):


Sample 4 (C-1-13):


Sample 5 (Ne-2-18):


Sample 6 (Ne+3-17):



Answer to activity question:



Justification:

Answers

Answer:

1(li_2_10)

li_1-10.

1_10:9

See image for question

Answers

Answer:

the energy produced as part of the reaction and balancing the equation accounts for the energy produced

What is the mass of 4.0 moles of sodium, Na?
– previous question: “how many atoms are present in 4.0mol of sodium?” = 2.4 x 10^24 atoms of Na in 4.0 moles.
need an explanation of how to figure this out (& info on how to do this in other problems as well, thank you) <3

Answers

Answer:

91.60 grams

Explanation:

For this specific problem, you are asked to find the weight of an element, when given moles. Other problems could give you a compound. In each case, you need to find the molar mass of the element or compound, that is, the weight (in grams) of 1 mole of the element or compound. Now that you know the molar mass of the element/compound, you can multiply by the amount of moles the equation the equation gives you to find the total weight.

In this problem, you are asked to find the mass of Sodium (Na). First, we need to look on the Periodic Table to find the Atomic Mass of Sodium. If we look, we find this to be 22.990 amu. Side note - when we find molar mass, amu and grams are interchangeable - you'll see here. This 22.990 amu is also the molar mass in GRAMS of 1 mole of sodium. The equation asks us to find the mass of 4 moles of sodium, so now we simply multiply by 4. 22.990 * 4 = 91.60 grams.

In summary, find the molar mass (1 mole) of the substance, by adding the amu's of each element (keeping mind the amount of each). Then, multiply this total number by the amount of moles that is given, and put your answer in moles.

Hope this helps

3. A reaction produces 14.2 grams of a product. The theoretical yield of that product
is 17.1 grams. Which of the statements are true? Select 2 that apply. (1 mark)
A. The percent yield of the product is 14.2%.
B. The percent yield of the product is 17.1%.
C. The percent yield of the product is 83.0%.
D. The percent yield of the product is 120.0%.
E. The actual yield of the product is 14.2 grams.
F. The actual yield of the product is 17.1 grams.

Answers

A reaction that produces 14.2 grams of a product and the theoretical yield of that product is 17.1 grams is true for the following statements :

The percent yield of the product is 83.0%

The actual yield of the product is 14.2 grams.

Percentage Yield:

Percent yield is the percent ratio of actual yield to the theoretical yield.

Mathematically,

percent yield = actual yield / theoretical yield x 100%

actual yield = 14.2 grams

theoretical yield = 17.1 grams

percentage yield = 14.2 / 17.1 × 100%

percentage yield = 83.0409356725 %

percentage yield = 83.0 %

Therefore,

The percent yield of the product is 83.0%

The actual yield of the product is 14.2 grams.

learn more on percentage yield here; https://brainly.com/question/4180677

how to convert washing soda into sodium silicate​

Answers

Answer:

Hope it helps!~ (sorry if you get it wrong or I got it wrong-)

Explanation:

Solutions of sodium silicates can be produced by treating a mixture of silica (usually as quartz sand), caustic soda, and water, with hot steam in a reactor.

~The Confuzzeled homan

how does a lone pair contribute to molecular shape

Answers

Answer:

It takes up space like an "invisible" atom.

Explanation:

It's just right dawg.



Question :-

who invited vaccination?​

Answers

Answer:

Edward Jenner

Explanation:

In 1796, he tested a vaccine on a boy with cowpox and he became immune to smallpox.

5 x 10^4 ÷ 2.5 x 10^2 =
a
2 x 10^2
b
12.5 x 10^2
c
.5 x 10^6
d
5 x 10^6

Answers

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[tex] \frac{5 \times {10}^{4} }{2.5 \times {10}^{2} } = 2 \times {10}^{2} \\ [/tex]

So the correct answer is (( a )) .

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5/2.5 = 2.5 and 10^4/10^2 = 10^4
The answer is 2.5 x 10^2

What is the difference between endothermic and exothermic changes?

Which type of change (exothermic or endothermic) is water freezing? Why? What type of matter is made of really hot and super excited (fast-moving) charged particles?

Answers

Answer:

An exothermic process releases heat, causing the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings. The frezing of water is an exothermic process because heat is being removed from the system. In gases the particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster. Hope this helped! :)

What is the volume of 4.35 moles of a gas at a pressure of 85.6 kPa and 26.0°C?

Answers

Answer:

125,066 litres

Explanation:


Need help with my work chemistry assignment grade 12 college work please

Answers

Answer:

A)0.450 mol N2

B)294 g NH4 NO3

Explanation:Step by step! make sure when you see underneath the multipication eqaution that we are deviding!The arrows is what we are dividing

A)36.0gN H4N O3×1 molN H4NO3×2mol N2

        ↑ 1                   ↑ 80.05gNH4NO3 ↑2mol N H4N O3

B)7.35molH2O×2mol N H4 N O3×80.05gN H4 N O3

    ↑    1                 ↑  4molH2O             ↑   1mol N H4N O3

5) 2 and for the how many moles it is 10.9

Hope this helps!

The horses on a carousel or merry-go-round are accelerating because

Answers

The speed of the horses in this carousel is constant, but the horses are accelerating because their direction is changing constantly. Acceleration toward the center of a curved or circular path is called centripetal acceleration.

!Please answer! Sort the chemical reactions based on whether they absorb or release energy


respiration in cells

producing electric current

photosynthesis

burning a candle

baking bread

activating a cold pack

Answers

Answer: respiration in cells, photosynthesis, activating a cold pack- absorb energy.

Producing electric current, burning a candle, baking bread- release energy.

Answer:

Releases Energy; burning a candle, producing electric current, and respiration in cells.

Absorbs Energy; activating a cold pack, baking bread, and photosynthesis.

Explanation:

Burning a candle releases heat energy into the surrounding area. The respiration process in cells does not produce any energy, so it must release it. Activating a cold pack absorbs energy in order to activate. Baking bread absorbs heat when baking, it releases it when cooling. Photosynthesis absorbs energy at the beginning of the process before releasing/using it.

This is 100% Correct, I checked this by taking the test and attached the image.

What’s the answer?????

Answers

potential energy

kinetic energy

kinetic energy

idk last sorry =(

What mass of HCL is consumed by the reaction of 5. 0 of magnesium?

Answers

I’m assuming you mean 5g of magnesium :)
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