Answer:
C
Explanation:
a hypothesis always comes first
Answer:
C
Explanation:
They form hypothesis first, then perform the experiment to test the hypothesis. After multiple experiments, they form a theory.
Thus C is correct
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Someone answer this please.
Answer: The percent composition of oxygen is 54.5%
Explanation:
Below I have attached my work through, but essentially the percent composition relies on finding the mass of the oxygens and dividing it by the mass of the whole compound. The masses of the elements can be found on the periodic table and added together to get a mass of the whole compound- ascorbic acid. Then, you turn this proportion into a percent by multiplying by 100%.
Answer:
54.5% is the correct answer
What is the net ionic equation for the reaction shown below?
AgNO3(aq) + NaCl(aq) --> AgCl(s) + NaNO3(aq)
Answer:
Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
Explanation:
Chemical equation:
AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
Balance chemical equation:
AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
Ionic equation
Ag⁺(aq)+ NO₃⁻(aq) + Na⁺(aq)+ Cl⁻(aq) → AgCl(s) + Na⁺(aq)+ NO₃⁻(aq)
Net ionic equation:
Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
The NO₃⁻((aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The AgCl can not be splitted into ions because it is present in solid form.
Spectator ions:
These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.
In a competition, an athlete throws a discus though the air. What was the average speed of the discus if it traveled 107 meters over a time of 12 seconds?
Answer:
8.92 m/s
Explanation:
Distance covered = 107 m
Time = 12 s
Average speed = ?
The relationship between the parameters is given by;
Average speed = Distance covered / Time
Average speed = 107 / 12
Average speed = 8.92 m/s
logically why all atoms are electrically neutral ?
ANSWER
An atom of element is electrically neutral because the number of positive protons are equal to number of negative electrons.
Answer:
Although thomson model of atom explained that atoms are electrically neutral, the results of this experiment carried by other scientists couldnot be explained by this model
_____ unit is the most widely used system of units in both science and business
Explanation:
I think the answer is metric system of units
because it is the most widely used system of units and its use in both science and business.
7. Which part moves the blood away from the heart?
10 bonta
O a. capillaries
b. veins
a carteries
O d. blood vessels
Answer:
Veins
Explanation:
Veins, which usually look blue, return blood to the heart.
help me please I need to pass.
Answer:
2 C Atoms
Explanation:
When you have coefficient of 2 next to a compound element, it indicates there are 2 of each compound element. In the compound element, there is one C Atom, and 2×1 is 2.
highlight the correct answer - polar or non polar
1. A (polar / non-polar) bond is one where there are more shared electrons grouped around one atom than the other.
2. A (polar / non-polar) bond is one where the electrons are evenly distributed between the two atoms sharing electrons.
3. A molecule with symmetry is (polar / non-polar).
4. A molecule that does not have symmetry is (polar / non-polar).
5. A (polar / non-polar) molecule has its valence electrons evenly distributed around the molecule.
6. A (polar / non-polar) molecule has one of its sides with more or fewer electrons than the other sides.
Answer:
1. Polar
2. Non-polar
3. Non-polar
4. Polar
5. Non-polar
6. Polar
Explanation:
Polar bonds are formed between molecules that share electrons unequally/unevenly. In a polar molecule, one atom is more electronegative than the other i.e it attracts/pulls more electrons than the other atom, hence, it ends up leaving the other atom with a positive charge i.e fewer electrons around its atom. Also, every molecule that has a symmetrical arrangement is NON-POLAR while the opposite is POLAR.
Based on this, the answers to the asked questions are in BOLD.
1. A POLAR bond is one where there are more shared electrons grouped around one atom than the other.
2. A NON-POLAR bond is one where the electrons are evenly distributed between the two atoms sharing electrons.
3. A molecule with symmetry is NON-POLAR
4. A molecule that does not have symmetry is POLAR.
5. A NON-POLAR molecule has its valence electrons evenly distributed around the molecule.
6. A POLAR molecule has one of its sides with more or fewer electrons than the other sides.
What does a ground wire do?
Answer:
A ground wire helps those positive charges get to the ground in a safe, direct and controlled way, where they can be discharged without the risk of electrical shock or fire. Shock Absorber Excess electrical charges are common in any home.
Explanation:
:3
If there is less ionization energy does that mean that it is more reactive? Why?
Answer:
The greater the ionization energy, the more difficult it is to remove an electron. The ionization energy may be an indicator of the reactivity of an element. Elements with a low ionization energy tend to be reducing agents and form cations, which in turn combine with anions to form salts.
Write any three possible structures for octane, C8H18 and give their IUPAC names
Answer:
Octane (n- octane) C8H184 - Methylheptane3- Ethylhexane2 ,2 - Dimethylhexanehope it helpsThe three possible structures for octane, C8H18 and give their IUPAC names are -
Octane2-Methylheptane2,2-Dimethylhexane(structures are attached)
The octane is a hydrocarbon with 8 carbon atoms and 18 hydrogen atoms. The molecular formula of octane is C8H18.
Carbon is a tetravalent atom that contains 4 electrons in the valence shell.carbon can donate its four electrons to form bonds with four other atoms.The structure of octane is drawn by first drawing a straight-chain or parent chain of 8 carbons and attaching 18 hydrogens on carbon to fulfill its tetravalency.The three possible structures for octane, C8H18 and give their IUPAC names are -
Octane2-Methylheptane2,2-DimethylhexaneLearn more about:
https://brainly.com/question/1370895
Which set of statements best explains the relationship between the parts of the respiratory system?
Answer:
The description of that same scenario is listed mostly in the explanation portion following.
Explanation:
This same respiratory system involves several lungs, as well as the systemic circulation concerning this same human heart, which operates in conjunction to pick up more oxygen as well as expel CO2 from the body.
These same lungs encourage O2 to pass both through alveoli via the blood capillaries surrounding off the front of the alveoli, that are otherwise interconnected to the arterial circulation, which carries O2 rich blood something to human heart through which O2 rich blood was indeed transported to many other blood vessels via the arteryConsequently, those system works together to promote the transmission of gas throughout tissues and organs and also to ensure sustainable the tissue functions required during metabolic functions.(4.2 x 10^8) + (2.6 x 10^6) *
422600000 or 4,226x 10^8
Answer:
422.6*10^6
Explanation:
(4.2*10^8)+(2.6*10^6)
4.2*10^8+2.6+10^6
(4.2*10^2+2.6)*10^6
(4.2*100+2.6)*10^6
(420+2.6)+10^6
Final Answer:
422.6*10^6
How many joules are needed to change the temperature of 40 g of water from 33 C to 23 C?
Answer:
Explanation:
Given parameters:
Mass of water = 40g
Initial temperature = 33°C
Final temperature = 23°C
Specific heat capacity of water = 4.2J/g°C
Unknown:
Quantity of heat = ?
Solution:
To solve this problem, we use the expression below;
H = m c Δt
H is the quantity of heat
m is the mass
c is the specific heat capacity
Δt is the change in temperature
H = 40 x 4.2 x (23 - 33) = -1680J
The water will have to lose 1680J of heat to bring it to that final temperature.
(30 points) Ahhhhhhh can someone help me :'))
I'm not smart and I don't understand how to solve this problem:
Octane, one of the major components of gasoline, burns in air according to this unbalanced equation:
C₈H₁₈ (l) + O₂ (g) ----> CO₂ (g) +H₂O
The formula balanced is: 2 C₈H₁₈ (l) + 50 O₂ (g) ----> 16 CO₂ (g) + 18 H₂O
a) What volume of O₂ at STP is needed to burn 702g (1.00L) of octane?
b) What volume of O₂ at 18°C and 0.975 atm is needed to burn 702g of octane?
Answer:
a. 137.93 dm3
b. 150.61 L
Answer:
C₈H₁₈
Explanation:
how many atoms are ln 6.31 moI of sodium sulfate
element compound mixture
which of the following best describes a single-replacement reaction?
A. one element takes the place of another in a compound
B. a compound breaks apart into separate elements
C. two elements combine to form a compound
D. Two elements switch places in two compounds
Answer:
One element takes the place of another in a compound
Explanation:
a p e x - just did the test
The statement best describes a single-replacement reaction as one element takes the place of another in a compound. The correct option is A.
What is a single replacement reaction?A single replacement reaction is one in which when the reaction happens, one element is substituted by another in a compound. It is also called displacement reaction. The replacing material will always be a pure element.
An example is Zn + 2HCl -> ZnCl₂ + H₂
Thus, the correct option is A. one element takes the place of another in a compound.
Learn more about single replacement reaction, here:
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Hree friends are talking about what they think causes shiny pennies to turn dull. Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time." Who do you agree with most and why?
Answer:
Deandre is correct.
Explanation:
When shiny pennies turn dull, due to getting rust. It gets cover with a layer of black or brown color on its surface on the exposure of air.
In this problem,
Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time.
Out of three friends, Deandre is correct. Shiny pennies turn dull because they're exposed to the air over time.
The original list from the Stockholm Convention on Persistent Organic Pollutants (POPs) of 12 hazardous chemicals, called the ____________________, which includes DDT and eight other chlorine-containing persistent pesticides, PCBs, dioxins, and furans.
Answer:
The dirty dozen.
Explanation:
This is mainly seen in the control of hazardous waste and its regulations through treaty in the control of persistent organic pollutant(POPs). This regulation is seen to occur in 12 widely used persistent organic pollutants; these are seen to have the ability to absorb and store tissues that make them fatty especially in humans and also animals found in the higher trophic levels or in the food web. That being said, it can be noted that the dirty dozen can move or even attain hundreds, or thousands of levels towards the environ and also in other cases, transporting them through air or water as the case may be.
Special thanks to anyone who answers this...
Answer:
94.74 moles of NO₂ are produced.
Explanation:
Given data:
Volume of oxygen gas = 3714 L
Temperature = 273 K
Pressure = 1 atm
Moles of NO₂ produced = ?
Solution:
Chemical equation:
4NH₃ + 7O₂ → 4NO₂ + 6H₂O
Number of moles of oxygen:
At STP one mole of any gas occupy 22.4 L volume. Thus, 3714 L gas contain,
3714 L× 1 mol / 22.4 L
165.8 mol
now we will compare the moles of oxygen and nitrogen dioxide.
O₂ : NO₂
7 : 4
165.8 : 4/7×165.8 = 94.74 mol
Thus, 94.74 moles of NO₂ are produced.
can someone help me with the unanswered questions pls sorry about bad quality
Answer:
I cant see it sorry
Explanation:
How many ants would 6 giant anteaters need to eat in one year to get the matter and energy they need? Write a simple formula to help you solve the problem. Then find the answer.
Answer:
180,000 ants
Explanation:
For this problem we can create the following simple formula to solve this problem...
f(x) = 6x
where the variable x represents the number of ants that a single Anteater needs to eat per day. After a quick online search we can see that a single Anteater eats roughly 30,000 ants per day. If we use this value and plug it into the simple formula we can get the total number of ants 6 anteaters need to eat to survive.
f(x) = 6 * 30,000
f(x) = 180,000
For the nitrogen fixation reaction 3H2(g) + N2(g) = 2NH3(g),
Kc = 6.0 x 10-2 at 500°C. If 0.253 M H2 and 0.044 M NH3 are
present at equilibrium, what is the equilibrium concentration
of N2?
The equilibrium concentration of N₂ : 1.992
Further explanationGiven
Kc = 6.0 x 10⁻² at 500°C
0.253 M H₂ and 0.044 M NH₃
Reaction
3H₂(g) + N₂(g) = 2NH₃(g)
Required
The equilibrium concentration of N₂
Solution
Kc for the reaction :
[tex]\tt Kc=\dfrac{[NH_3]^2}{[H_2]^3[N_2]}\\\\0.06=\dfrac{0.044^2}{0.253^3\times [N_2]}\\\\(N_2]=1.992[/tex]
Hi can anyone answer these two distance and time questions
If 125.0g of nitrogen is reacted with 125.0g of hydrogen, what is the theoretical yield of the reaction? What is the excess reactant? What is the limiting reactant? Show your work.
The theoretical yield of the reaction : 151.64 g
The limiting reactant : N₂
The excess reactant : H₂
Further explanationReaction
N₂+3H₂⇒2NH₃
A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients(mol ratio), and the smaller become a limiting reactant
mass of N₂=125 g
mol N₂(MW=28 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{125}{28}=4.46[/tex]
mass H₂ = 125 g
mol H₂(MW= 2 g/mol) :
[tex]\tt mol=\dfrac{125}{2}=62.5[/tex]
From the equation, mol ratio N₂ : H₂ = 1 : 3
Limiting reactant : N₂ : H₂ =
[tex]\tt \dfrac{4.46}{1}\div \dfrac{62.5}{3}=4.46\div 20.8[/tex]
N₂ : limiting reactant
H₂ : excess reactant
mol NH₃ based on limiting(N₂) (from equation N₂ : NH₃ = 1 : 2)
[tex]\tt mol~NH_3=\dfrac{2}{1}\times 4.46=8.92[/tex]
mass NH₃ (MW=17 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=8.92\times 17=151.64[/tex]
1 What is the approximate altitude of Polaris when viewed from New York City?
Answer:
44° to 45°
Explanation:
The altitude of Polaris star when viewed from New York City is somewhat between 44° to 45°. However, Polaris is directly overhead at the North Pole (90° of latitude); in other words, the angle between Polaris and the horizon at the North Pole is 90°. This angle is called "the altitude" of Polaris.
What element does beryllium resemble (in terms of electrons) when it loses 2 electrons?
Answer: Helium
Explanation: Beryllium (Be) has an electron configuration of 2-2. Losing two electrons will leave it with two electrons in the first shell, resembling Helium.
Can a larger, cooler object have more TOTAL kinetic energy than a smaller, warmer object?
Answer:Hotter objects have a higher average kinetic energy and a higher temperature ; cooler objects have a lower average kinetic energy and a lower temperature.
Explanation:
what is this i need help please
Answer:
umm probly glucose and oxygen.??
Explanation: