While he was researching and writing that book in the 1860s, Mendeleyev made the discovery that led to his most famous achievement. He noticed certain recurring patterns between different groups of elements and, using existing knowledge of the elements' chemical and physical properties, he was able to make further connections. He systematically arranged the dozens of known elements by atomic weight in a grid-like diagram; following this system, he could even predict the qualities of still-unknown elements. In 1869, Mendeleyev formally presented his discovery of the periodic law to the Russian Chemical Society.
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how many elements belong to the alkali metal family
Answer:
six
Explanation:
check your periodic table
What makes inertia important in that activity?
What is the mass of 1.20 × 1023 atoms of phosphorus?
show your work, please.
1227.6
Explanation:
po ang sagot khit i calculate nyo
65,000(0.08 x 200x 0.004) / (800x300)
Perform the following operations giving the proper number as a benefit get figures in the answer.
Help
Answer:
Use calculator but first group them one by one and open the bracket by solving them accordingly
The number we get by this operation is 0.016. This number can be taken based on the rules for significant figures.
What is significant figures?The number of significant figures is the number of digits that are known with certainty plus the last one having some uncertainty. All non zero values are significant and zero preceding first non zero digit is not significant .
For example in 65000, there are only two significant figures. Similarly in 0.08 only one significant digit is present. Now when we multiply two decimal numbers, the result can only have as many decimal places as there are in the value with fewest decimal places.
First, multiply the numbers inside the bracket. As per the above rule, the result should contain only two decimal places.
(0.08 ×200×0.004) = 0.06
Multiply by 65000 - 0.06×65000 = 3900
Now divide it by the multiplication product (800× 300), 240000 we get as follows:
3900÷240000 = 0.016
Hence the result of this operation is 0.016.
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What is the total number of neutrons in an atom of O-18? a) 18 b) 16 c) 10 d) 8
Answer:
There are 10 neutrons
Explanation:
Because the atomic number is 8 and the isotope number is 18 (which is the collective protons and neutrons), we can do
18-8=10
Answer:
10
Explanation:
8 proton because it is oxygen
10 neutron because 18-8
what are the statement of ethanol
Answer:
Density 0.78945 g/cm3 (at 20 °C)
Melting point −114.14 ± 0.03 °C (−173.45 ± 0.05 °F; 159.01 ± 0.03 K)
Boiling point 78.23 ± 0.09 °C (172.81 ± 0.16 °F; 351.38 ± 0.09 K)
Solubility in water Miscible
Explanation:
mark brainliest
a student is given a mixture of sand and salt. describe a method the student could use to separate the mixture.
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution.
Solute is the substance which is in small amount in a solution. Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
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Ethanoic acid is a weak acid because
Is a carboxylic acid
Does not irritate the skin
Is not completely ionized in water
Produces one hydrogen ion per molecule
Answer:
is not completely ionized in water
The ethanoic acid (acetic acid) is considered as a weak acid because it does not releases all of its hydrogen in water, rather it dissociates partially and establishes an equilibrium with its conjugate base.
ANSWER ASAP!!!! WILL GIVE BRAINLIEST IF RIGHT
I need help with this
Answer:
129 units cubed
Explanation:
There are ten spaces between 120 and 130, so we can infer that each line represents a change in volume of 1 unit. The volume of the substance in the graduated cylinder looks like it's 1 under 130, so its volume is 129 units.
Hopefully this was helpful! :)
The temperature of a gas is increased. Which statement best explains the effect that this has on the motion of gas
particles?
Answer:
The average kinetic energy increases, and the particles collide more frequently.
Explanation:
in space why is it black in space except the planets
Answer:
because space is near-perfect vacuum - meaning it has exceedingly few particles- there is virtually nothing in the space between stars and planets to scatter light to our eyes
Where does the energy of a hurricane come from? (1 point)
O the Sun
O strong winds
O Earth's spin
O Earth's moon
Answer:
strong winds come from the energy of a hurricane
The energy of a hurricane come from strong wind. The Taino Native American term hurricane, which translates to "bad spirit of the wind," is where the word hurricane originates.
What is hurricane ?A tropical storm that has sustained winds of 74 mph or greater is referred regarded as a hurricane. A storm's eye typically measures 20 to 30 miles in width and can reach distances of 400 miles. Storms can be dangerous because of their torrential downpours, strong gusts, and storm surges.
When warm, humid air begins to rise over water, hurricanes emerge. Cooler air replaces the rising air. Large clouds and thunderstorms continue to grow as a result of this process. Thanks to the earth's Coriolis Effect, these thunderstorms are still expanding and starting to rotate.
Thus, option B is correct.
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please help me I need it now
Answer:
Ok for the question you can make up your own
If you can't make up your own tell me so I can try my best to come up with questions
1. Answer: Since and last are adverbs so am not sure how that part going to go
Type of Adverb for since is: Time
Type of Adverb for last is : Time
2. Question:
Answer: happily
Type: Manner
Hopes this helps you.
which of the following are physical properties of nonmentals
You did not provide any options.
guys- my science teacher doesn't teach, he just says go on schoology
Do all particles pass right through the atoms undeflected?
Answer:
no when Rutherford performed the gold foil experiment he bombard the atom alpha particles and two other scientist, Geiger and Marsden came with great news saying the particles suffered serious deflection
A chemical property is a change in _____.
hardness
density
composition of matter
physical state
Answer:
Composition of matter
11) When sodium metal is subjected to violet light, it causes the photoelectric effect. However, red light does not affect
the sodium. Explain this phenomena.
The phenomena in which violet light causes photoelectric effect and red light does not is because red light does not achieve the minimum frequency for the phenomenon to occur but violet light does.
The phenomenon in which a substance emits electrons when light is incident upon it is called the photoelectric effect.
This electron would not be emitted if the frequency of the light does not exceed a minimum frequency called the threshold frequency.
Since in the case of the sodium metal, violet light causes the photoelectric effect while red light does not.
This implies that red light does not exceed the minimum frequency for the photoelectric effect to occur, but violet light does thereby causing the photoelectric effect to occur.
So, the phenomena in which violet light causes photoelectric effect and red light does not is because red light does not achieve the minimum frequency for the phenomenon to occur but violet light does.
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assuming that no heat is lost to the surroundings, what is the final temperature of the mixture?
if the products of a reaction have higher energy than the reactants, then the reaction...
Answer:
Explanation:If the products of a reaction have higher energy than the reactants, then the reaction...
whats valency of nitrogen in N2O3, N2O5 and NO
Answer:
Valency of nitrogen in the given compounds:
N₂O₃ = +3
N₂O₅ = +5
NO = +2
-TheUnknownScientist 72
Heat is transferred from a fire to potatoes that are sitting on top of the coals.
Which type of heat transfer is occurring?
Answer: Is it Conduction?
Explanation:
could you help answer these two question
Answer:
number 29 is D
Explanation: When the moon orbits the earth some of the light reflects off the moon, making it visible on the Earth.
I dont know how to answer 28 fully, is there a picture?
What fraction of the original atoms of the radioactive sample will remain after the given number of half-lives has passed?
Answer:
1/8
Explanation:
[tex] \frac{1}{ {2}^{3} } = \frac{1}{8} [/tex]
Mark brainliest please
A GIRL WAIKS 10M NORTH,15M EAST AND THEN FINALLY 20MSOUTH FIND HER DISPLACEMENT
Answer:
see this
Explanation:
What are compounds????????????????
Answer:
Compounds are pure substance consisting of two or more different atoms
Answer:
I hope this help
Explanation:
pls brainliest
Though hydrochloric acid is formed inside our body, it is not called organic acid. Why?
Explanation:
Hydrochloric acid does not consider as organic acid because of the absence of carbon in it.
hope it helps
Explain why the structure of Copper [ 1s², 2s², 2p⁶, 3s², 3p⁶, 3d¹⁰,4s¹] is more stable than [ 1s², 2s², 2p⁶, 3s, 3p²⁶, 3d⁹,4s² ].
A subshell which is 100% full or 50% full is more stable than subshells which are partially filled with a number of electrons less than or greater than half the number of electrons which can be held by the subshell.
Explanation:
Which item is a good example of potential energy?
A thrown baseball
O Electricity
O A rock
A battery
