Answer:
The invention of the wheel had an important impact on farming.
Answer:
C
Explanation:
Just took the test
(a) Convert the following:
50 cm into m
Answer:
0.5m
Explanation:
Who wrote the first modern chemical textbook?
O Antoine Lavoisier
O Dmitri Mendeleev
O Henry Moseley
O Johann Dobereiner
Answer:
Antoine Lavoisier
Explanation:
Antoine Lavoisier wrote the first modern textbook. It is the answer.
The modern chemical textbook was written by Antoine Lavoisier. The book is titled as Elementary Treaties On Chemistry.
Who is Antoine Lavoisier?Antoine Lavoisier is known as the father of modern chemistry. He contributed a lot to revolutionize chemistry. Antoine Lavoisier proposed the law of conservation of mass.
Nomenclature of chemical compounds was proposed by Antoine Lavoisier. He studied about the combustion and respiration in detail and the results are written in the book Elementary Treaties On Chemistry.
Hence, the first modern chemical textbook was written by Antoine Lavoisier.
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HELP QUICK ILL GIVE YOU BRAINLIEST AND 25 POINTS! bromine (br) has four energy levels. name 2 other elements that would have four energy levels.
Answer:
titanium and potassium
Explanation:
Answer: geranium and krypton
Explanation: hope this helps
I have no clue on what to do
Answer:
A.
Explanation
Because it is totally irrelevant to what the question is asking.
Calculate the mass of oxygen needed to react 10g of calcium to form calcium oxide. 2 Ca + O2→2 CaO
Answer:
Explanation:
1122 g CaO.
I hope I helped you! :)
The mass of oxygen needed to react 10 grams of calcium to form calcium oxide is 4.0 grams.
Given:
The reaction:
[tex]2Ca+O_2\rightarrow CaO[/tex]
Mass of calcium = 10 g
To find:
The mass of oxygen needed to react 10 grams of calcium to form calcium oxide.
Solution:
[tex]2Ca+O_2\rightarrow CaO[/tex]
Mass of calcium = 10 g
Moles of calcium = [tex]\frac{10 g}{40.078 g/mol}=0.25 mol[/tex]
According to reaction, 2 moles of calcium reacts with oxygen, then 0.25 moles of calcium will react with:
[tex]=\frac{1}{2}\times 0.25 mol=0.125 \text{ mol of }O_2[/tex]
Mass of 0.125 moles of oxygen gas:
[tex]0.125 mol\times 31.998 g/mol=3.99975 g\approx 4.0 g[/tex]
The mass of oxygen needed to react 10 grams of calcium to form calcium oxide is 4.0 grams.
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Plsss helpppp pls fast :(
Answer:
valance electrons are located in the outermost shell/ outermost energy levels. it determines how they will react their reactivity.
HELP ME WITH THIS QUESTION PLEASE
ASAP
When a cup is placed on a table, which force prevents the cup from falling to the ground?
A gravitational force
B.
normal force
с.
resistance force
D.
tension force
Answer:
B. normal force
Explanation:
When a cup is placed on a table, the forces acting on the cup are the gravitational force and the normal force. The gravitational force acts in the downward direction while the normal force acts in an upward direction. It is clear that the gravitational force is balanced by the normal force. So, the correct option is (b) " normal force ".
When a substance freezes, it changes from the liquid phase to the solid phase because of its _____.
intermolecular bonding
ability to fit the shape of its container
compactness
molecular bonding
Answer:
intermolecular bonding
Explanation:
A cylinder with 10 mL of coconut oil has a mass of 9.3 g. What is the density of the oil? Round to the nearest hundredth.
Answer:
0.93 grams per milliliter
Explanation:
Density is the division of mass by volume. It is how "hefty" an object is; for example, wood isn't very "hefty" but metal is. The density is measured in mass over volume, so it is 9.3/10. After applying units, it is 0.93 grams per milliliter.
What is a carcinogen? a. a toxin linked to an increased risk of cancer b. a non-carbon based chemical c. a type of pollution that can be traced to a specific source d. a type of pollution that cannot be traced to a specific source
Answer:
Explanation:
a i think
Answer:
it would (a)
Explanation:
carcinogen is a substance that gives your tissues a higher chance of getting cancer
why matter looks and feels different depending on the object
Answer:
because the volume
Explanation:
The MSDS for benzene indicates that it is a clear liquid that has a substantial vapor pressure. It has a health rating of
2, a fire rating of 3, and a reactivity rating of 0. It is a cancer-causing agent.
Based on this information, which siatement about benzene is accurate?
Benzene readily reacts with moist air.
Benzene explodes if the container is shaken.
Benzene must be kept away from flames.
Benzene must be stored under high pressure.
Based on the provided information, the statement that is accurate about benzene is that it must be kept away from flames. This is because benzene has a high flammability rating of 3, which indicates that it can ignite and burn easily.
Additionally, the MSDS states that benzene has a substantial vapor pressure, which means it can easily evaporate into the air and form flammable mixtures with air.
The other statements are not accurate. Benzene does not readily react with moist air or explode if the container is shaken. It also does not need to be stored under high pressure. However, benzene is a cancer-causing agent, so it is important to handle it with care and follow proper safety precautions.
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• An element is shiny, brittle, and a poor conductor of electricity.
Which of the following is the best classification for the element?
2. You water three sunflower plants with salt water. Each plant receives a different
concentration of salt solutions. A fourth plant receives pure water. After a
two-week period, the height is measured.
IV
I
DV
CG
Answer:
Independent variable, is the amount of salt water received by each plant
Dependent variable, is the height of each plant
Control group, is the fourth plant that received pure water.
Note: The question is incomplete. The complete question is as follows: For the following experiments, define the independent variable (IV), dependent variable (DV) and control group (CG).
2. You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured.
Explanation:
Independent variable: An independent variable is a variable that an experimenter changes or controls and which has a direct effect on the dependent variable.
In the experiment above, the independent variable is the amount of salt water received by each plant because it is under the control of the experimenter and also is thought to have a direct effect on the height of plants.
Dependent variable: A dependent variable is a variable that is being measured or studied in an experiment, and it depends on the independent variable for its results.
The height of the plants is the dependent variable as it depends on the amount of salt water the plant receives.
Control group: The control group is the group in an experiment or study that does not receive the treatment as the other groups being studied and as such, is not influenced by the independent variable. Therefore, it is used as a standard for the other groups under study.
In this experiment, the control group is the fourth plant that received pure water.
Block A has a mass of 5g and a volume of 15mL. What is the density of block A? Will it float in water (density of water is 1.0 g/mL) Don't forget the units!! PLSSSS PLSSS PLSSS HELP I WILL MARK BRAINLIEST AND HELP WITH UR QUESTIONS I PROMISE!!!!
Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass of block = 5 g
volume = 15 mL
The density of the block is
[tex]density = \frac{5}{15} = \frac{1}{3} \\ = 0.33333333...[/tex]
We have the final answer as
0.33 g/mLThe block will float on water since it's density is less than that of water which is 1 g/mL
Hope this helps you
Please help me with this question.
Answer:
12?
Explanation:
Answer:
8
Explanation:
haploid is half
Which shell is the outermost for oxygen?
A 192
B. 292
C. 252P
D. 2P
Answer:
D is the answer
How does quantitative data apply to the scientific method?
Express the following in regular notation:
3.4 x 10-1
A)O 34
B)O 0.34
C)0 3.4
D)0.00034
How is crystallization used in the pharmaceutical industry (simple answer please)
Answer:
CRYSTALLIZATION :IMPORTANT IN THE PHARMACEUTICAL INDUSTRY.IT IS A SEPARATION PROCESS FOR INTERMEDIATE AND A FINAL STEP IN PHARMACEUTICAL INGREDIENTS.A BRAINLIEST PLEEAAAASEWhich of the following is TRUE? *
The sun gives off solar energy which solar panels can convert into mechanical energy
A roller coaster in motion has potential energy but a roller coaster waiting at the top of a drop has kinetic energy
When we exercise we burn chemical energy, but give off thermal energy
A person on a bike uses thermal energy to pedal the bike, and potential energy helps keep the tires rotating
Answer:
I believe the answer is A
Explanation:
Would convection occur if Earth's mantle were a box 30 km on a side?
Answer:
No.
Explanation:
No, convection does not occur if Earth's mantle were a box 30 km on a side because convection needs medium for the movement of heat energy from one place to another. Convection and conduction are two processes which needs medium for its movement while radiation does not need any medium for its movement. If there is a empty space present between two substances so convection does not occur.
A student measures the mass of a substance as 1.7132kg and it's volume as 0.65l. What is the density substance in g/mL? Round your answer to the correct number of significant figures
Answer:
The substance has a density of 2.636 grams per mililiter.
Explanation:
We must remember that density ([tex]\rho[/tex]), measured in grams per mililiters, is the mass of the substance ([tex]m[/tex]), measured in grams, divided by its volume ([tex]V[/tex]), measured in mililiters. That is:
[tex]\rho = \frac{m}{V}[/tex]
In addition, a kilogram equals 1000 grams and a liter equals 1000 mililiters. If we know that [tex]m = 1713.2\,g[/tex] and [tex]V = 650\,mL[/tex], then:
[tex]\rho = \frac{1713.2\,g}{650\,mL}[/tex]
[tex]\rho = 2.636\,\frac{g}{mL}[/tex]
The substance has a density of 2.636 grams per mililiter.
How many years are in 72,000 sec?
Answer:
72000 seconds equals 20 hours.
Explanation:
Sir Isaac Newton developed a law that describes the gravity between bodies of matter called _________________________________.
Answer:
Universal law of gravitation
The liquid state of matter can be described as
Answer:
The liquid state of matter is an intermediate phase between solid and gas. ... Liquids will flow and fill the lowest portion of a container, taking on the shape of the container but not changing in volume. The limited amount of space between particles means that liquids have only very limited compressibility
Explanation:
A liquid is a nearly incompressible fluid with a nearly constant volume regardless of pressure that adapts to the shape of its container. It belongs to one of the four basic states of matter.
Volume retention and conformity to the shape of a liquid's container are two of its most noticeable physical characteristics. When a liquid substance is poured into a container, it conforms to the shape of the container and will stay inside the container so long as the liquid state persists.
The intermolecular forces of attraction in a liquid state of matter are stronger than those in a gaseous state but weaker than those in a solid state.
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What word starting with “J” was a period that dinosaurs existed within?
Answer:
Jurassic period
Hope this helps!
true or false
The atomic number of an element can be used to find the number of protons and neutrons in a neutral atom
The most appropriate way to measure a volume of soda
Answer:
measure in cups or fluid ounces
Explanation:
Answer:
Liters
Explanation:
Trust me
Please help! If a forensic chemist discovers evidence through examination which would prove a person guilty of a crime, why then might this person not be convicted?
Explanation: You cannot be convicted of a crime without evidence. You cannot be convicted of a state crime. You cannot be convicted of a federal crime. If there is no evidence against you, under the law, it simply is not possible for the prosecutor's office to obtain a conviction at trial. So, when you do have evidence it is really impossible to not get convicted unless the judge truly believes your side of the story and declares you not guilty.
I hope this helped :) If not i'm sorry!