Answer:
Lead is a chemical element with symbol Pb and atomic number 82.
3-4. When something interests you, how do you make a hypothesis?
5-6. Why is it important to take a good notes when you are conducting an experiment?
7-8. What is the last step in the scientific method? Explain.
9-10. Name one thing you want to investigate this year for a scientific project? Why?
Answer:
3-4. I think we should research the topic, and make a assumption based on what you learned.
5-6.There are times when a scientist is unable to answer his own question. If he has taken good notes, another scientist may come along later and use his notes to find the answer. Every year there is new knowledge. The scientific method is a step-by-step process.
7-8.The final step of the scientific process is to report your results. Scientists generally report their results in scientific journals, where each report has been checked over and verified by other scientists in a process called peer review.
9-10. I don't know this one.
when two atoms share four valence electrons the shared electrons form a/an ____
Into what genre does a novel fit that
takes place in a made-up world and
has events that couldn't really
happen?
A. non-fiction
B. mystery
C. fantasy
Answer:
A. non fiction or a ajami to download
The body of knowledge that deals with Earth and its place in the universe is called _____________?
Answer:
Cosmology is a branch of astronomy that involves the origin and evolution of the universe, from the Big Bang to today and on into the future. According to NASA, the definition of cosmology is "the scientific study of the large scale properties of the universe as a whole."
Which formula can be used to calculate the percent yield?
a.(Theoretical yield ÷ actual yield) x 100
b.(Actual yield ÷ theoretical yield) x 100
c.(Amount of reactants ÷ amount of products) x 100
d.(Amount of products ÷ amount of reactants) x 100
Which benzene derivative would be the least reactive in an electrophilic aromatic substitution reaction
what is the density of a 5 mL sample of 1.95g of Gold
Answer:
density=mass/volume
=1.95/5 = 0.39 g(mL)-¹
Which direction does heat flow from
Answer:
A
Explanation:
hot to cold; jus took the quiz;)
how to find the average speed of something
Answer:
if you want to find average speed so u need to use this formula
Average speed = [tex]\frac{Total Displacement}{Total Time}[/tex]
Part A
In the year 2012, an estimated amount of 31.6 billion metric tons (1 metric ton = 1000 kg) of carbon dioxide (CO2) was emitted worldwide due to fossil fuel combustion
and cement production. Express this mass of CO2 in grams without exponential notation, using an appropriate metric prefix
The mass of CO₂ in grams without exponential notation and with the appropriate metric prefix is 31.6 Eg.
First, let's calculate the amount of mass in grams of 31.6 billion metric tons.
Knowing that 1 metric ton is equal to 1000 kg, 31.6 billion metric tons is:
[tex]m = \frac{1000 kg}{1 \: metric \: ton}*\frac{1000 g}{1 kg}*31.6 \cdot 10^{12} \: metric \: ton = 3.16 \cdot 10^{19} g[/tex]
The metric prefix that is close to the above result is exa (E), which is equal to 10¹⁸.
Therefore, the mass of CO₂ in grams without exponential notation and with the appropriate metric prefix is 31.6 Eg (exa-gram).
To learn more about metric prefixes go here: https://brainly.com/question/20712978?referrer=searchResults
I hope it helps you!
Please help me out in this question am giving the brainliest
Question 18(Multiple Choice Worth 5 points)
(03.02 MC)
Which of the following elements has properties different than the rest?
H
K
N
O
Answer:
H
hydrogen have different properties
In a fission reaction a 235U nucleus captures a neutron. This results in the products 141Ba and 92Kr along with how many neutrons?
A. 1.
B. 2.
C. 3.
D. 5.
lidocain có tính bazơ không
Answer:
Lidocain là cơ bản.
Tôi hy vọng câu trả lời của tôi là hữu ích cho bạn.
A lab team places 0.250g of an unknown solid acid in an Erlenmeyer flask. They neutralize the solid acid with 15.0ml of 0.210 M Na(OH)(aq). One mole of the acid reacts with one mole of the base. Calculate the molar mass of the unknown solid acid O 158 g/mol 0 7.9 g/mol 79.4 g/mol 0 763 g/mol
Answer:
Molar mass of the unknown acid is 79 grams
Explanation:
We have to first get moles in 15.0 ml of sodium hydroxide solution:
[tex]{ \sf{1 \: l \: of \:NaOH \: contains \: 0.210 \: moles }} \\ { \sf{0.015 \: l \: of \: NaOH \: contain \: (0.015 \times 0.210) \: moles }} \\ { \underline{ = 0.00315 \: moles \: of \: NaOH}}[/tex]
since mole ratio of acid : base is 1 : 1, so;
moles of acid that reacted is 0.00315 moles of the unknown acid.
then we've to get molar mass:
[tex]{ \sf{0.00315 \: moles \: of \: acid \: weigh \: 0.250 \: g}} \\ { \sf{1 \: mole \: of \: acid \: weighs \: ( \frac{1 \times 0.250}{0.00315} ) \: g}} \\ { \underline{ = 79.4 \: g \approx79 \: grams}}[/tex]
When a liquid is at its boiling point, the vapor pressure of the liquid
Acrylonitrile and ethyl acetate have the same boiling point: 77.2ºC. In one to two sentences, explain what outcome you would expect if a mixture of these two substances were distilled (SHORT ANSWER)
Acrylonitrile and ethyl acetate will be collected together since they both have the same boiling point.
The method of distillation highly depends on the difference between the boiling points of the Acrylonitrile and ethyl acetate.
Since they have the same boiling point, the two substances turn into vapor at the same temperature and are collected simultaneously.
Hence separation is not achieved by distillation.
Learn more: https://brainly.com/question/15946045
Answer:
They would boil at the same rate. Basically meaning, that they would both be finished distilling at the same time.
Explanation:
This is what I put (this is for you to revise and it has not been graded yet DO NOT CHEAT with this answer just take in the info and revise it)
Selenium, an element required nutritionally in trace quantities, forms compounds analogous to sulfur. Name the following ions.
a. SeO_4^2-
b. Se^2-
c. HSe^-
d. HSeO_3^-.
The names of ion are:
[tex]Selenate = SeO_4^{2-}\\Selenide = Se^{-2}\\Hydroselenide = HSe^-\\Hydrogenselenite = HSeO_3^-\\[/tex]
Explanation:
Sulfur forms various compounds such as sulfates, sulfites, sulfides, hydrosulfides, hydrogensulfites.The symbols of these ions are:[tex]Sulfate = SO_4^{2-}\\Sulfite = SO_3^{2-}\\Sulfide = S^{-2}\\Hydrosulfide = HS^-\\Hydrogensulfite = HSO_3^-\\[/tex]
According to the question, selenium also forms compounds analogous to sulfur so the name of the given ions of selenium will be in analogy to that of the sulfur compound.
[tex]Selenate = SeO_4^{2-}\\Selenide = Se^{-2}\\Hydroselenide = HSe^-\\Hydrogenselenite = HSeO_3^-\\[/tex]
Learn more about sulfur and selenium here
brainly.com/question/515173?referrer=searchResults
brainly.com/question/2396770?referrer=searchResults
How can the Swartz process be modified to work for bacteria? Explain.
Answer:
https://swartzbiotechnologylab.sites.stanford.edu/research
Explanation:
Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
Swartz reaction?Frederick Jean Edmond Swarts first reported this procedure in 1892. Heating the alkyl chloride or alkyl bromide in the presence of heavy metal fluorides like AGF, Hg2F2, CoF2, or SbF3 causes this reaction.
Swartz process can be used to modify work for bacteria. Bacterial biofilms are collections of microorganisms where the cells are immersed in an extracellular polymeric matrix that the bacteria have self-produced.
In contrast to planktonic bacteria, which are in a state of free movement in a bulk solution, this situation is very different.
Applications:
In this process, alkyl fluorides are created.Fluorinated aliphatic organic molecules, or Freons, are produced via a different variation of the same process.Anhydrous hydrogen fluoride is fluorinated to produce Freons in the presence of antimony salts, which exhibit the oxidation states +3 and +5.Therefore, Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
To learn more about the Swartz process, refer to the link:
https://brainly.com/question/10019079
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The density of Silver is 10.5 g/mL. How much mass would be present given a silver cube
with a volume of 25.0 mL?
PLEASE HELP ASAP
Answer:
m=dxv
= 10.5 x 965 = 10132.5 rounded off to 10100 g
Explanation:
Choose the best possible answer for Q.No. A, B, and C.
The following is an acid-base reaction between sulfuric acid and aluminum hydroxide. Use the provided molar masses to answer the questions below:
molar
mass
3 H2SO4
+
2 Al(OH)3
⟶
Al2(SO4)3
+
6 H2O
g/mol
98.08
78.00
342.15
18.02
Note: You need to upload the documents for A, B, and C to show your work.
A. How many moles of sulfuric acid would be required to form 65.21g of Water?
moles of H2SO4 = ________
[ Select ]
B. How many grams of Aluminum Sulfate could be formed if 197.0g aluminum hydroxide reacts with sulfuric acid?
mass of Al2(SO4)3 = ________
[ Select ]
C. To determine the concentration of a sulfuric acid sample, a titration is performed with the above reaction. What is the concentration of the sulfuric acid if a 15.00mL sample reached its titration endpoint with 29.26mL of 0.2855M Al(OH)3?
Molarity of H2SO4 = ________
[ Select ]
Answer:
c i think
Explanation:
How would life be different without penicillin
Answer:
Without new antibiotics, common infections and minor injuries could become life-threatening and major surgeries and chemotherapy impossible because the treatments we have been using for years are no longer effective.
Who developed the gas law that relates pressure and temperature?
Explanation:
physicist Robert Boyle
Answer: Boyle
Explanation: Educere Answer
Write differences between reactants and products.
Reactants - The substance which participate in a chemical reaction are called reactants.
[tex] \rm \: Example - H_2 \: , \: O_2[/tex]
Product - The substance which are formed by chemical reaction between the reactants are called product.
[tex]\rm \: Example - H_2 O[/tex]
Explanation:
reactant is a substance that is present at
the start of a chemical reaction.
product is a substance
that is present at the end of a chemical
reaction.
How are electrons arranged around an atom?
Answer:
Viewed simply, electrons are arranged in shells around an atom's nucleus. Electrons closest to the nucleus will have the lowest energy. Electrons further away from the nucleus will have higher energy.
Answer:
Electrons are placed in the lower energy level first and when this is completely filled, we move on to the second energy level and so on. The way the electrons are arranged in an atom is called the atom's electronic structure or electronic configuration. The maximum number of electrons that the first shell can contain is 2.
Explanation:
PLEASE HELP!!!!!!!!! WILL MARK BRAINLIEST
Answer:
19.278049929737628457607385688801
Explanation:
Volume = L * W * H
Volume = 17.78 * 9.21 * 4.45 = 728.70441
Density = Mass / Volume
Mass = 14,048
14,048 / 728.70441 = 19.278049929737628457607385688801
Density = 19.278049929737628457607385688801
Explanation:
So density = mass/volume
Using this formula we'll solve the question.
mass = 14,048g/1000 = 14.048 kg
volume = 17.78/100 x 9.21/100 x 4.45/100
volume = 0.3143 m³
density = 14.048 kg/ 0.3143 m³
density = 44.69 kg/m³
round off to = 44.7 kg/m³
CHAPTER 8 FORCE AND MOTION
Choose the S.I. unit for pressure.
1. Watt
2. Joule
3. Pascal
4.Newton
1. A substance with 1 or 2 electrons in the valence shell is called what?
A. Insulator
B. Conductor
C. Molecule
D. Semiconductor
Answer:
B. Conductor
Explanation:
What is the correct clases for this drugs
Compazine
heelp me please
and
Promethazine
Answer:
Compazine belongs to a class of drugs called Antiemetic Agents; Antipsychotics, Phenothiazine.
will it sink or float?
giving brainlist
Answer:
Air will Float
Ice will Float.
aluminium will sink
Lead. has to sink
Gold will sink
Ethanol it will nor sink or float. it is like neutral.
methanol will Float.
Explanation:
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