5. Scientists always develop a plan when they try to learn something about our natural world. Which
sequence correctly shows the steps scientists follow in their plan?
A. make observations, develop an idea, obtain evidence, suggest an explanation
B. obtain evidence, suggest an explanation, develop an idea, make observations
C. suggest an explanation, obtain evidence, make observations, develop an idea
D. develop an idea, suggest an explanation, obtain evidence, make observations
Imagine you have two beakers. Both beakers are filled with the same amount of water. The water in both beakers is the same temperature as well. You add 50 g of Substance A to the first beaker and 50 g of Substance B to the second beaker. After stirring both beakers, there is a small pile of Substance A at the bottom of the first beaker. None of Substance B is visible in the second beaker. Which of the following statements is true?
A. Substance B is not soluble in water
B. Substance A is more soluble in water than Substance B
C. Substance A is less soluble in water than Substance B
D. Substance A is not soluble in water
Substance A is less soluble in water than Substance B.
In this experiment, we can see that small amount of substance A is present at the bottom of the beaker which means that some amount of substance A does not dissolve in water.
While on the other hand, no substance B is present at the bottom of beaker which shows that all the substance B is dissolved in water so we can made a conclusion that Substance A is less soluble in water than Substance B.
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Fast pls due rn help fast pls
Answer:
Section a:
1. stratosphere
2. radio waves
3. nitrogen, oxygen
4. humidity
5. smoke, fog
Section b:
1. ozone layer
2. stratosphere
3. carbon dioxide (CO2)
4. smoke
5. tropical areas
Section c:
1. false, it is clear
Hope those help and are all correct
who is credited with developing the periodic table
Answer:
Dimitri mendleev and Albert something. I forgot his last name. I think ghorso. Albert ghorso.
Hurry. NO Spam! Write the neutralization reaction that occurs between HF and LiOH.
Answer:
HF + LiOH = LiF + H2O.
Explanation:
Hydofluoric acid is a weak acid the solution would be slightly basic due to the following equilibrium (condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.)
Hope that helps. x
Which two observations are evidence that a chemical change is happening?
A. A yellow liquid forms as a yellow solid is slowly heated.
I B. Bubbles of gas are released when a solid is combined with a
liquid.
I c. Solid crystals form as the temperature of a liquid is lowered.
D. Light and heat are given off after a spark ignites a substance,
can somebody please help me here ? i wanna make sure of my answer..
Answer:
[Unfortunately] Answer is A
Explanation:
You should know that 'liquid' is a state of matter and aqueous means that there is water present.
-It is mentioned that barium chloride is a solution. So you can cut off the C option.
-Barium sulfate is a salt which means it's a solid, so you can cut off the D option.
We now have A and B as the only options remaining.
-Dilute sulfuric acid is definitely not a liquid because water is present. (dilute indicates that there is a greater proportion of water)
The answer should be A.
Which of the following is not a use of radioactive isotopes?
a) Energy generation
b) Carbon dating
c) Chemotherapy
d) Radiotherapy
Answer:
i belive the answer you are looking for is A.. hope this helps!
Explanation:
im not really 100% certain of this answer due to the fact i am a little rusty.
How do chemists predict the shapes of molecules?
Due to the repulsion between electrons, valence electrons will be arranged as close to each other as possible.
Due to the attraction between electrons, valence electrons will be arranged as close to each other as possible.
Due to the repulsion between electrons, valence electrons will be arranged as far apart from each other as possible.
Chemists can't predict the shape of molecules, because the attractive forces between valence electrons are unpredictable.
A. Due to the repulsion between electrons, valence electrons will be arranged as close to each other as possible.
The approximate shape of a molecule can often be predicted by using what is called the valence-shell electron-pair repulsion (VSEPR) model.Electrons in bonds and in lone pairs can be thought of as a charge cloud that repels one another and stay as far apart possible, thus causing molecules to assume specific shapes.The shape of a molecule is determined by the location of the nuclei and its electrons.Therefore, the correct option is A.
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2.3g of sodium metal is burned completely in oxygen of air.
(Na =23, O =16, at STP : 32g of O2 has 22.4L)
Find mass of the obtained oxide?
Find volume of the required air?
Answer:
mass of Na2O= 3.1 grams
volume of O2= 0.56 L
Explanation:
First what you need to do is establish the balanced equation for the reaction that they're giving you. In this case would be:
4Na + O2 > 2Na2O
And then, you can read the stequiometry of the reaction:
4 moles of Na react with one mole of oxygen to produce 2 moles of sodium oxide.
So now you know that you have 2.3 grams of sodium so you have to obtain the quantity of moles that are present in 2.3 grams of sodium. The molar mass the (the grams by which you will have exactly one mole) so all you have to do is divide 2.3g ÷ 23g/mol= 0.1 mol
So here you have 0.1 mol of sodium, and you know for a fact that for each 4 moles of sodium, one mole of oxygen reacts, so you simply divide the quantity of moles of sodium you have by the 4 moles of oxygen present in the balanced equation.
0.1 moles ÷ 4 moles = 0.025.
So for each 0.1 moles of sodium that react, 0.025 moles of Oxygen react.
Now what you need to do is to find the limitant reactor (the reactor that's according to the comparison to the balanced equation is in a smaller ratio to the other element, that would be in excess.
In this case, both elements are in a ratio that respects the balanced equation so neither of them is in excess or is limitant.
Now, to determine the amount of Na2O, you simply know that one mole of oxygen react to produce to moles of sodium oxide, So all you have to do is establish the factor of conversion:
0.025 moles O2 x 2 moles Na2O/ 1 mol O2= 0.05 moles of Na2O
Then you convert that to grams by multiplying 0.05 by the molar mass of Sodium oxide and it will be:
0.05 mol Na2O x 62 g/mol= 3.1 grams of Na2O
Now what you need to do is find the volume by which O2 is reacting in the reaction so you can use the equation of the ideal gas law.
PV=nRT at standard temperature and pressure (273 K and 1 Atm)
P=Pressure
V=Volume
n=Number of atoms
R=constant of gases (0.082 Atm L/ mol K)
T=Temperature
V=nRT/P (because you need to find the volume)
V= (0.025 mol)(0.082)(273 K)/1 atm
V=0.56 L
And there you go :)
Kingdom:
Domain:
I am made of many cells. My cells have
an organized nucleus, I have two
parents and eat food.
Guess Who?
please help
Answer:
SORRY IM LATE! at least i saw it.
Explanation:
Kingdom is Eucaryota
domain is eucarya
How do you determine the group and period of an element based on its electron configuration?
Answer:
If you are given with the atomic number of an element you can find it's period number and group number. The period number is related to the number of electron occupied shells in the element and the period number is linked to its valence electrons.
Explanation:
hope it helps luv <3
which describes an attribute of nonrenewable resources
Answer:
atributes of nonrenewable recources are things you cant re use after 1 use like gas
Explanation:
Answer: the answer is b. Are unlimited
Explanation:
what is the nature of the p-o bond in phosphorus pentoxide (p2o5)?
Answer:
the nature of the bond is covalent.
covalent bonds are bonds between 2 NON-METAL elements. since phosphorus and oxygen are both non-metals, the bond formed between them is covalent.
hope this answers your question!
BRAINLIEST TO FIRST RIGHT ANSWER
Use the key above to interpret the following incomplete chemical reaction.
Select the statements at apply in order to complete the model. (Choose 3)
A) The number of atoms in the products must be equal to the reactants.
B) One diatomic oxygen should be removed from the reactant side.
C) One unbonded carbon atom should be added to the product side of the equation
D) One carbon atom and two oxygen atoms are needed to balance the equation.
E) One carbon dioxide molecule should be added to the product side of the equation.
Answer:
Carbon dioxide molecule
Answer:a , d ,e
Explanation:
jusy took quiz
21. Which of the following is the best way to clean up an acid spill?
A. Wash down the acid spill with plenty of water.
B. Wipe up the acid spill with paper towel.
C. Spread sawdust on the acid spill to absorb it.
D. Neutralize the acid spill with a base; then wash it with plenty of water.
T1
Is bleach liquid starch?
Yes or No
Answer:
O it's not
Explanation:
Have a great day!
Does pure water conduct electricity? If not, what can we do to make it conduct electricity?.
Iron reacts with oxygen and water to create rust and hydrogen gas as shown in the chemical equation. What mass of rust, to the nearest hundredth gram, is produced in this reaction?
A) 4.3 g
B) 5.8 g
C) 16.8 g
D) 29.4 g
Answer:
i think its 5.8
Explanation:
predict the product 1-bromo propane is treated with sodium metal
When 1-bromo propane is reacted with sodium metal, the propane and sodium bromide are formed.
Propane and sodium bromide are produced when the 1-bromo propane is reacted with sodium metal. The Bromine which is present in the 2-bromopropane is removed through hydrogenation and combines with the sodium metal which results in the production of propane and sodium bromide.So we can conclude that propane and sodium bromide are produced when the 1-bromo propane is reacted with sodium metal.Learn more about 1-bromo propane here: https://brainly.com/question/25597694
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30g of glucose and 20 g common salt is dissolved in 500 mL of water to make solution. Calculate the concentration of a (a) glucose and (b) common salt in terms of mass by mass percentage of the solution. (Density of water = 1 g/mL)
Answer:
The answer of a is 5.45% and b is 3.64%
Explanation:
Density of water = 1 g/mL
∴ Mass of water (solvent) = 500 g
Mass of solute (glucose) = 30 g
Mass of solute (common salt) = 20g
Mass of solution = (30 + 20 + 500) g = 550 g
a.)Mass percentage of solution for glucose
= Mass of solute (gucose)/Mass of solution × 100
= 30/550 x 100
= 5.45 %
b.)Mass percentage of solution for common salt
= Mass of solute (common salt)/Mass of solution × 100
= 20/550 × 100
= 3.64 %
Thus, The answer of a is 5.45% and b is 3.64%
-TheUnknownScientist 72
Answer:
5.45%
and
3.64%
hope it's helpful
Which statement describes how a substance melts?(1 point) Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other.
Answer:
Molecules in the substance gain kinetic energy and then become less tightly bound to each other.
Explanation:
According to the forces of attraction , for a substance to melt molecules in the substance gain kinetic energy and then become less tightly bound to each other.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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Boron and antimony are good elements to use as
Answer: Semiconductors
Explanation:
Draw the Complete Electron Energy Level Diagram (or the Orbital Diagram) for Ru+3
Answer:
A
Explanation:
refer to textbook
What has more particles: a mole of hydrogen or a mole of uranium?
Answer
hydrogen
Explanation:
Read the following chemical equations.
Reaction 1: 2KI + H2O2 2KOH + 12
Reaction 2: Cl2 + H2 → 2HCI
Which of the following statements is true for both the chemical equations?
A. I is oxidized in reaction 1 and Cl2 is oxidized in reaction 2.
B. I is reduced in reaction 1 and Cl2 is reduced in reaction 2.
C. I is oxidized in reaction 1 and Cl2 is reduced in reaction 2.
D. I is reduced in reaction 1 and Cl2 is oxidized in reaction 2.
This problem is providing two reduction-oxidation (redox) reactions in which the oxidized and reduced species can be identified by firstly setting the oxidation number of each element:
Reaction 1: 2K⁺I⁻ + H₂⁺O₂⁻ ⇒2K⁺O⁻²H⁺ + I₂⁰
Reaction 2: Cl₂⁰ + H₂⁰ ⇒ 2H⁺CI⁻
Next, we can see that iodine is being oxidized and oxygen reduced in reaction #1 and chlorine is being reduced and hydrogen oxidized in reaction #2 because the oxidized species increase the oxidation number whereas the reduced ones decrease it.
In such a way, the correct choice is C.
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(Redox reactions) https://brainly.com/question/13978139Which non metal is highly reactive
Answer:
element fluorineThe most reactive nonmetals reside in the upper right portion of the periodic table. Since the noble gases are a special group because of their lack of reactivity, the element fluorine is the most reactive nonmetal.How is the polarity of a bond different from the polarity of a molecule?
Answer:
A polar bond is one where the charge distribution between the two atoms in the bond is unequal. A polar molecule is one where the charge distribution around the molecule is not symmetric. It results from having polar bonds and also a molecular structure where the bond polarities do not cancel.
Explanation:
What is the dependent variable in this graph
Answer:
height (mm)
Explanation:
The independent variable belongs on the x-axis (horizontal line) of the graph, and the dependent variable belongs on the y-axis (vertical line).
Do you think the amount of fat will affect its melting point?