Answer:
3
Explanation:
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
6. Which part leads the blood to the heart?
10 points
a. capillaries
b. veins
O c. arteries
d. blood vessels
Answer:
Your answer should be D
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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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.
what is this i need help please
Answer:
umm probly glucose and oxygen.??
Explanation:
When would evaporation be a good method for separating the parts of a mixture?
A.When the densities of the compound are different
B. When some of the components are magnetic
C. When some of the components are very small
D.When the boiling points of the components are different
Answer:
D.When the boiling points of the components are different
Explanation:
I believe the formal name for this procedure is actually distillation.
The more bonds an atom can make, the more likely it is to combine with other atoms in different ways Which element is most likely able to make the greatest variety of bonds? a. nitrogen b. hydrogen c. oxygen d. carbon
Answer:
D. Carbon.
Explanation:
Carbon can be mixed with Many things. for example, YOU are mostly made out of carbon. Other things include furniture, clothing, plastics, charcoal, pencil led, diamonds, and gas.
Answer:
b xplanation:
_____ 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.
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.
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
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:
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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
how many atoms are ln 6.31 moI of sodium sulfate
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.
5gm of hydrogen diffused through a porus membrane
in 30 minutes. Find the time required to diffuse
the some amount of so2 gas at identhal conditions.
169.71 minutes
Further explanationGiven
Rate of diffused of Hydrogen=5 gm/30 min
Required
The time required for SO₂
Solution
Graham's law: the rate of effusion of a gas is inversely proportional to the square root of its molar masses or
the effusion rates of two gases = the square root of the inverse of their molar masses:
[tex]\tt \dfrac{r_1}{r_2}=\sqrt{\dfrac{M_2}{M_1} }[/tex]
r₁=5gm/30 min
M₁=molar weight of H₂-hydrogen= 2 g/mol
M₂=molar weight of SO₂-sulfur dioxide= 64 g/mol
[tex]\tt \dfrac{5/30}{r_2}=\sqrt{\dfrac{64}{2} }\\\\\dfrac{5/30}{r_2}=4\sqrt{2}\\\\\dfrac{5}{30}=r_2.4\sqrt{2}\\\\r_2=\dfrac{5}{30\times 4\sqrt{2} }=\dfrac{\sqrt{2} }{48}[/tex]
the time required (for the same amount=5 gm) :
[tex]\tt \dfrac{5}{x}=\dfrac{\sqrt{2} }{48}\rightarrow x=120\sqrt{2}=169.71 minute[/tex]
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]
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.
1. Magnesium chloride solution reacts with silver nitrate solution to form magnesium nitrate
solution and silver chloride.
Equation: MgCl2 (s) + 2 AgNO3 (aq) → Mg(NO3)2 (aq) + 2 AgCl (s)
Find the mass of silver chloride formed if
(a) 20 cm of 2.5 mol/dm^3 of magnesium chloride solution is used.
(6) 20 cm of 2.5 g/dm^3 of magnesium chloride solution is used.
a. 1,4332 g
b. 7.54~g
Further explanationGiven
Reaction
MgCl2 (s) + 2 AgNO3 (aq) → Mg(NO3)2 (aq) + 2 AgCl (s)
20 cm of 2.5 mol/dm^3 of MgCl2
20 cm of 2.5 g/dm^3 of MgCl2
Required
the mass of silver chloride - AgCl
Solution
a. mol MgCl2 :
[tex]\tt 20~cm^3=20\times 10^{-3}~dm^3\\\\mol=M\times V\\\\mol=2.5~mol/dm^3\times 20\times 10^{-3}DM^3=0.05[/tex]
From equation, mol AgCl = 2 x mol MgCl2=2 x 0.05=0.1
mass AgCl(MW=143,32 g/mol)= 0.1 x 143,32=1,4332 g
b. mol MgCl2 (MW=95.211 /mol):
[tex]\tt mol=M\times V\\\\mol=\dfrac{2.5~g/dm^3}{95,211 g/mol}=0.0263~mol/dm^3[/tex]
From equation, mol AgCl = 2 x mol MgCl2=2 x 0.0263=0.0526
mass AgCl(MW=143,32 g/mol)= 0.0526 x 143,32=7.54~g
element compound mixture
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.
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.
can someone help me with the unanswered questions pls sorry about bad quality
Answer:
I cant see it sorry
Explanation:
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.
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.
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.(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:
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:
(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
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.
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