What did ancient astronomers not know about eclipses?

Answers

Answer 1

Answer:

yes of course everyone know eclipse in ancient January 2004 eclipse was founded in other country's


Related Questions

What is the molality of a solution containing 15 g NaCl dissolved in 50 g of water

Answers

Answer:

cdjkekendnekekekeknenwkwkwkwnrnrnrjejjwjwksnsjnrheifjfuufjeenenej

Hopes this helps:

Answer: 5.132 mol/kg

How I got the answer I looked it up. Please mark as brainlist if it’s right.

In the reaction between CH4 and O2, if 25.0 g of CO2 are produced, what is the minimum amount of each reactant needed?
PLS HELP

Answers

Answer:

25 gram

Explanation:

the minimum amount of the reactant needed is equal to the mass of the product because of the law of conservation of mass ok

4. Suppose in the first part of the experiment you did not heat strong enough to
decompose the potassium chlorate, how would this affect your result?​

Answers

when you strongly heat the potassium chlorate it leaves oxygen if you'll not heat it strongly to decompose it the oxygen would not release and the compound will remain thermally unstable.

Heating of Potassium Chlorate results into decomposition of Potassium Chloride and Oxygen gas.

When KClO₃ is heated strongly, it breaks down, releasing oxygen gas and leaving behind a thermally stable (i.e., heat-insensitive) solid residue of an ionic potassium compound.

If enough heat is not provided to potassium chlorate then it will not decompose into its substituent products and also some of the potassium chloride product splattered out of the crucible during the heating process.

Learn more:

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Please help this is due tonight

Answers

4. the nervous system uses electrical impulses to send messages through neurons while endocrine glands use hormones to send messages

5. Hormones are released from the endocrine glands

6. a. neck
b. Chest

7. help regulate important functions, such as growth, blood pressure and reproduction; it is small and small and bean shaped.

8. produces hormones that regulate the body's metabolic rate controlling heart, muscle and digestive function, brain development.

9. regulate your metabolism, immune system, blood pressure, respond to stress etc.

10. “enzymes” - break down sugars, fats, and starches

11. cells are unable to use glucose (can’t break down sugar to use as energy)

What is the pH if the [H+] concentration is 3 x10^-13​

Answers

Answer:

pH = 12.52

Explanation:

Given that,

The [H+] concentration is [tex]3\times 10^{-13}[/tex].

We need to find its pH.

We know that, the definition of pH is as follows :

[tex]pH=-log[H^+][/tex]

Put all the values,

[tex]pH=-log[3\times 10^{-13}]\\\\pH=12.52[/tex]

So, the pH is 12.52.

g What is the relationship between the moles of the limiting reagent and the change in temperature (i.e. directly proportional or indirectly proportional)

Answers

Answer:

number of moles is inversely proportional to the Temperature

Explanation:

As we know

PV = nRT

where P is the pressure

V is the volume

n is the number of moles

R is the gas constant

and T is the temperature

If we see the equation, we can find that n is inversely proportional to the Temperature

What are 3 different ways we can preserve our ecosystem and what makes your 3 ways effective?

Answers

Answer:

1. Stop throwing trash and bottles in lakes because it can have our animals live longer and not have issues

2. Reducing the number of bags you use from the store because they can end up being on the ground and cause plenty of damage around us

3. probably trying not to having fires because there is alot of problems that are happening like the wildfires in californa which is leading to our animals and trees dying

hope this helps

have a good day :)

Explanation:

ill give brainliest :D

how many grams of kcl are produced from 11.5 grams?

Answers

Answer:

approximately 15.1 grams.

Explanation:

The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.

change 25 grams of potassium chlorate to moles.

calculate the gram molecular mass of potassium chlorate.

Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.

1 K x 39 grams/mole

+1 Cl x 35.4 grams/ mole

+3 O x 16 grams/ mole

= 122.4 grams / mole Potassium Chlorate

25

122.4

= moles.

2.05 moles of Potassium Chlorate.

There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.

2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.

Find the gram molecular mass of Potassium Chloride.

1 K x 39 = 39

+1 Cl x 35.4 = 35.4

= 74.4 grams / mole.

2.05 moles x 74.4 grams/ mole = 15.2 grams

Answer:

idont know nalimotan ko hhhh...

5. Calculate the number of molecules of carbon tetrachloride in 0.32 mol of
carbon tetrachloride.

Answers

To Find :

The number of molecules of carbon tetrachloride in 0.32 mol of

carbon tetrachloride.

Solution :

We know, 1 mole of any element/compound contains [tex]6.022 \times 10^{23}[/tex] number of atoms/molecules.

So, Number of molecules in 0.32 mol are :

[tex]n = 0.32 \times 6.022 \times 10^{23}\\\\n = 1.93 \times 10^{23}[/tex]

Therefore, number of molecules of carbon tetrachloride in 0.32 mol of

carbon tetrachloride are [tex]1.93 \times 10^{23}[/tex].

How many isomers are there with the following descriptions? Alcohols with the formula ‍ ‍ Answer Two Bromoalkanes with the formula ‍ ‍ Answer

Answers

Answer:

Three isomers

Isomer I  CH3-CHOH - CH3

Isomer 2 CH2OH-CH2-CH3

Isomer 3  CH3-CH2-CH2OH

Explanation:

Complete question

How many isomers are there with the following descriptions?

a) Alcohol with formula C3H8O

Solution

There are total 3 carbon atoms in this alcohol. Hence, there will be three isomers of Alcohol with formula C3H8O .

The three isomers will comprise of alcohol group (OH) attached to the three carbon atoms one by one.

Isomer I  CH3-CHOH - CH3

Isomer 2 CH2OH-CH2-CH3

Isomer 3  CH3-CH2-CH2OH

How many total carbon atoms are in the structure 2 methyl, 3, 4 diethyl decane?

12
15
14
10

Answers

Answer:B

15 carbon atoms

Which compounds are most likely ionic? compounds A and B O compounds B and C compounds C and D O compounds D and A​

Answers

Answer:

compounds D and A

Explanation:

The ionic compound can conduct electricity therefore, the compounds A and D are most likely ionic. Therefore, option (4) is correct.

What are ionic compounds?

Ionic compounds can be defined as crystalline solids produced by closely packed ions with opposite charges. The formation of an Ionic compound takes place when metal reacts with non-metal.

In ionic compounds, the ions of the compound are generally linked together by ionic bonds. The ions of an atom are formed by gaining or losing electrons in order to get the noble gas electronic configuration.

In a reaction, the metals are generally electropositive so they can lose electrons to complete their octet while non-metals will gain electrons from the metals to complete their octet.

Ionic compounds can conduct electricity in a molten state and aqueous solution because then they have free ions that can move from one place to another to conduct an electric current.

Learn more about ionic compounds, here:

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#SPJ6

PLSS HELPP ME i dont knowww

Answers

Answer:

non polar. polar ionic substance

El osmio es un metal sólido que tiene una densidad
de 22 600 kg/m?, ¿qué volumen ocuparán 100 g de
este metal?

Answers

Respuesta:

4.42 × 10⁻⁶ m³

Explicación:

Paso 1: Información provista

Densidad del osmio (ρ): 22600 kg/m³Masa de osmio (m): 100 g

Paso 2: Convertir 100 g a kilogramos

Usaremos el factor de conversion 1 kg = 1000 g.

100 g × 1 kg/1000 g = 0.100 kg

Paso 3: Calcular el volumen ocupado por 0.100 kg de osmio

La densidad es una propiedad intensiva, igual al cociente entre la masa y el volumen.

ρ = m/V

V = m/ρ

V = 0.100 kg / (22600 kg/m³) = 4.42 × 10⁻⁶ m³

If the half-life of Carbon-14 is 5700 years, how many years would it take a sample to decay from 1 gram to 31.3 mg

Answers

Answer:

28500 years

Explanation:

Applying,

A = A'([tex]2^{x/y}[/tex])............... Equation 1

Where A = Original mass of Carbon-14, A' = Final mass of carbon-14 after decaying, x = total time, y = half-life.

From the question,

Given: A = 1 g, A' = 31.3 mg = 0.0313 g, y = 5700 years.

Substitute these values into equation 1

1 = 0.0313([tex]2^{x/5700}[/tex])

[tex]2^{x/5700}[/tex] = 1/0.0313

[tex]2^{x/5700}[/tex]  = 31.95

[tex]2^{x/5700}[/tex] ≈ 32

[tex]2^{x/5700}[/tex] ≈ 2⁵

Equating the base and solve for x

x/5700 ≈ 5

x ≈ 5×5700

x ≈ 28500 years

4. Which should be done after a volcanic eruption?
A. Go to your neighbor.
B. Prepare your emergency kit.
C. Ignore what is happening around.
D. Stay in the evacuation center until it is safe to return.
5. Which is NOT true about volcanic preparedness?
A. Make a plan.
B. Prepare an emergency kit.
C. Cover your nose with a damp cloth.
D. Do not follow the instructions of the authorities.​

Answers

Answer:

4. D sounds like the best option.

5. D is the correct answer.

Explanation:

You're Welcome

A 45-year-old woman comes to a clinic with complaints of morning stiffness in her ankle joints, worse on rising in the morning and improving during the day. Her discomfort is responsive to aspirin. She has also been fatigued and weak. During the last week, she has noticed that her wrist and ankle joints on both sides of her body are also painful and swollen. Blood is drawn to test for rheumatoid factor and antinuclear antibody. Synovial fluid is aspirated and analyzed. Results from analysis of the synovial fluid rule out crystal deposition diseases, such as gout and pseudogout, and no infectious microorganisms are seen.

Required:
a. What can be the possible cause of a false-positive RF assay?
b. Do the patient's clinical symptoms and laboratory results support a diagnosis 5. If so, what diagnosis would be the first choice, and why?

Answers

Answer:

In all the patients with rheumatoid arthritis RF is not present. It can also be witnessed in patients with conditions like hepatitis, bacterial endocarditis, and tuberculosis. Some of the reasons that can also produce false-positive results for RF assay are lipemic, hemolyzed, or heavily contaminated serum, other rheumatic diseases like systemic lupus erythematous, reading test results post the specified time of two minutes, and due to some of the chronic infectious diseases like hepatitis, tuberculosis, and syphilis.

b. The symptoms of the oatient like inflammation and pain in joints and the results of the lab indicate that the synovial fluid is drying and formation of crystal is taking place. These are the conditions that suggests the existence of rheumatoid arthritis.

c. In the given case, the first choice diagnosis would be the blood test that would show the presence of anti-CCP antibodies and the drying of synovial fluid. The presence of anti-CCP antibodies results in wear and tear in the joints, thus showing the diseased conditions.

A water bottle is cooled to -115c. What is the new pressure

Answers

.........................................................................

Answer:

129

Explanation:

Who used scientific investigations to study atoms?
Check all that apply.
Dalton
Democritus
Rutherford
Thomson

Answers

Answer:

Rutherford used scientific investigation to study atoms.

Scientist who used scientific investigations to study atoms is Rutherford.

What are atoms?

Atoms are the basic fundamental or functional unit of any substance present in the nature.

Rutherford is also known as the father of nuclear physics and he did scientific investigation on the massive part of atom called nucleus he discovered that there are two types of radiation, coming from the uranium atom are alpha and beta particles.

Scientific investigation is a method in which scientist will study, perform and observe results for the experiment.

Hence Rutherford used scientific investigation.

To know more about Scientific investigation, visit the below link:
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calculate the molecular mass of sodium trioxocarbonate (iv) decahydrate. hints (H= 1, C=12, O=16, Na=23​

Answers

Given :

A compound sodium trioxocarbonate (iv) decahydrate.

To Find :

The molecular mass of sodium trioxocarbonate (iv) decahydrate.

Solution :

We know, molecular formula of sodium trioxocarbonate (iv) decahydrate is :

Na₂CO₃.10H₂O

Now, we can calculate its molecular mass :

M = ( 2 × 23 ) + 12 + ( 3 × 16 ) + 10 × ( 1 × 2 + 16)

M = 46 + 12 + 48 + ( 10 × 18 )

M = 286 gram/mol

Hence, this is the required solution.

16. A solution is made by dissolving 25 g of NaCl in enough water to make 1.0 L of solution. Assume the density of the solution is 1.0 g/cm3. Calculate the molarity and molality of the solution.

Answers

Answer:

The molarity will be "0.43 M" and molality will be "0.43 m".

Explanation:

Given that:

mass of NaCl,

= 25 g

Volume of solution,

= 1 L

Density of solution,

= 1 gm/cm³

Now,

The weight of solvent will be:

= [tex]Volume\times density[/tex]

= [tex]1\times 1[/tex]

= [tex]1 \ kg[/tex]

The mole of NaCl will be:

= [tex]\frac{mass}{Molar \ mass}[/tex]

= [tex]\frac{25}{58.44}[/tex]

= [tex]0.43[/tex]

hence,

The molarity will be:

= [tex]\frac{number \ of \ mole}{Volume \ of \ solution}[/tex]

= [tex]\frac{0.43}{1}[/tex]

= [tex]0.43 \ M[/tex]

The molality will be:

= [tex]\frac{mole \ of \ solute}{Weight \ of \ solvent}[/tex]

= [tex]\frac{0.43}{1}[/tex]

= [tex]0.43 \ m[/tex]

If a point is chosen inside the square, what
is the probability that it will also be inside the
circle?
1

Answers

Point to be present exactly at midway between center and circumference of circle (let’s say radius = r) should lie at circumference of circle of radius r/2.

Favorable outcome = 2*pi*r/2

Total outcome = Point can be anywhere inside the circle of radius r = Area of circle = pi * r * r

Probability = (2*pi*r/2) / pi * r* r = 1/r.

Not completely sure about correctness . Waiting for comments to verify.

best way to hump girls

Answers

Answer:

When they're sleeping

Explanation:

After they've been drugged

What is the temperature of 0.750 mol of a gas stored in a 6,050 mL cylinder al 221 atm?
atm
Use and
molek
5.24K
138 K
246 K

Answers

Answer:

T = 246 K

Explanation:

Given that,

Number of moles, n = 0.750 mol

The volume of the cylinder, V = 6850 mL = 6.85 L

Pressure of the gas, P = 2.21 atm

We need to find the temperature of the gas stored in the cylinder. We know that,

PV= nRT

Where

R is gas constant

T is temperature

So,

[tex]T=\dfrac{PV}{nR}\\\\T=\dfrac{2.21\times 6.85}{0.75\times 0.0821}\\T=245.85\ K[/tex]

or

T = 246 K

So, the temperature of the gas is equal to 246 K.

plz help me asap i need this plz



Why is it sometimes not practical to use to scale models when representing objects in space?

Answers

I think it’s because from earth things may appear smaller smaller in space where in actuality in space it can be way larger

How many grams are in 0.375 mol LiBr? (MM LiBr=86.85 g/mol)
O 32.6 g
O 0.00315 g
O 0043 g
O 86.8 g

Answers

Answer:

32.57g

Explanation:

mass = mole x molar mass

mass of LiBr = 0.375 x 86.85

mass = 32.57g

Which of the following statements is FALSE. Select one: A. Two of the statements are false. B. In the synthesis of aspirin, the main impurities are salicylic acid and acetic acid. C. Aspirin was purified in the lab by recrystallizing the crude aspirin. The melting point of the purified aspirin is expected to be lower than the melting point of crude aspirin. D. In the analysis of aspirin, the greater the amount of salicylic acid impurity in the aspirin, the smaller the amount of NaOH needed for the hydrolysis of aspirin. E. If the crude aspirin is not entirely pure, the temperature range at which it melts will be larger than pure aspirin.

Answers

Answer:

Aspirin was purified in the lab by recrystallizing the crude aspirin. The melting point of the purified aspirin is expected to be lower than the melting point of crude aspirin.

Explanation:

The presence of impurities in a sample lowers the melting point of the impure substance. Hence the melting point of an impure substance is always less than the melting point of the corresponding pure substance.

Bearing this in mind, the statement "Aspirin was purified in the lab by recrystallizing the crude aspirin. The melting point of the purified aspirin is expected to be lower than the melting point of crude aspirin." is found to be false since impure substances tend to have a slightly lower melting point than the pure substance, and a broader melting temperature range.

10. The lithium-ion in a lithium-ion battery moves from one side to the other by

A. moving through the cathode.
B. moving through the anode.
C. passing through the separator.
D. passing through the device.

Answers

I can confirm it’s A: Moving through the cathode

Question 18 (Multiple Choice Worth 2 points)
(12.02 LC)
What type of adaptation relates to the stages of growth and reproduction of plants?
Inherited trait
O Life cycle difference
O Learned behavior
O Physical characteristic

Answers

Answer:

the answer should be Life Cicle Difference.

Answer: Option (D) Is the correct  Life cycle difference

Explanation: Hope it helps!

Good luck!!!

Difference between brain and spinal cord
Pls help

Answers

They are both part of the nervous system but the brain is housed inside the skull and it controls most of the activities of the body. In higher organisms such as humans and other vertebrates, it is the centre of learning. Then the spinal cord is a tube-like structure that begins from the end of the brain and ends at the bottom of the backbone. The spinal cord is made up of nerves that carry information between the brain and the rest of the body.
The brain is housed inside the cranium and the spinal cord is enclosed inside the vertebral column
Other Questions
Omar, Amare, and Jack paid a total of $68.25 for dinner and tickets to a concert. The concerttickets cost $9.75 each. If the 3 friends split the dinner bill equally, how much did each friendspend on dinner? George Washington supported a policy of ______when he told Americans to avoid getting involved in foreign affairs' A)annexationB)diplomacyC)isolationism D)democracy In his "Address to Students at Moscow State University," President Reagan expresses the idea that a new era is being ushered in by the power of human imagination.Which two universal ideas will most likely represent the message that resonates with the students of Moscow State University?beauty of simplicitythe role of technology in societythe disadvantages of materialismindividual versus societychange versus tradition Which of the following is a common role adjustment for a couple during the empty nest stage? * The expression 4x* represents 144 2.(05.05 LC)A chef is serving a lunch special with 1 sandwich and 2 corn cobs per plate. If there are 5 sandwiches and 14 com cobs, what is the theoretical yield? (3 pointO 2 plates4 plates5 platesO 7 plates Read the short story. Lynn, Sarah, and Keanna have been friends for over three years. Because they are all good singers, their high school chorus director has entered them into a local singing competition. The winner of the contest will advance to a state competition and have the opportunity to sing on television. All of the girls think that would be really exciting. Which conclusion would readers find most satisfying All are examples of events that led to the end of the Cold War EXCEPT:a. Berlin Wall was torn downb. Germany was reunitedc. Soviet Union dissolvedd. Panama was annexed to Columbia ______ involves separately and simultaneously sterilizing the food and its container before packaging the food. cuanto dura un partido de futbol salA? [tex] \\ \\ \\ \\ \\ \\ \\ [/tex][tex] \sqrt{25 \times 25} [/tex][tex] \\ \\ \\ \\ [/tex] Corrigan was the sole proprietor of Tastee Burgers, a restaurant. In 2018, Bergdahl allegedly suffered from food poisoning after eating lunch at Tastee Burgers. In 2019, Corrigan died and left everything, including Tastee Burgers, by will to his niece, Layla. Layla then reorganized Tastee Burgers as a limited liability corporation with her best friend Horowitz. In 2020, Bergdahl filed a lawsuit for $500,000 against Tastee Burgers for long term health effects from the food poisoning. Layla and Horowitz have denied responsibility for the injuries and seek a dismissal of the lawsuit. What should the court decide Find the equation (in terms of x ) of the line through the points (-3,4) and (1,-8) Please help with each ASAP!!!! lable the dna molecule FAST! 1.What are the solutions to the equation 0 = x2-x-6? I NEED PLEASE IT WOULD REALLY HELP ME ALOT !!NO LINK OR ZOOMS 1) During the Middle Ages, people looked to the Bible for truth.True or false Jorge's friend Anna planted a garden with the same ratio of tulips to daisies. Anna's garden has 21 tulips. How many total flowers are in Anna's garden? What are the 3 main forces from outside the earth that also cause changes on its surface?