Answer:
4.65 g x 1 mol/4.0026 g/mol = 1.162 mol helium
Explanation:
An apple has been left out, and it is starting to rot. Which of the following is the best method to slow down the chemical changes that are occurring?
The best method is to keep rinsing the apple with water every hour.
The best method is to keep the apple in a cooler place.
The best method is to put the apple in the sun to warm it up.
The best method is to wrap the apple in plastic.
Write the nuclear equation for the beta decay
of calcium-45.
Answer:
on https://www.ck12.org/book/peoples-physics-concepts/section/20.1/
Explanation:
it shows for calcium 45 and maybe a possible equation on 3/4th's scroll down?
2) Two students are running in a cross country race. One has a mass of 60 kg, while the other has a mass of 70 kg. If they are both running with a speed of 7 m/s, which has more momentum? Why?
Answer:
The second student with mass 70kg has more momentum
Explanation:
Using the formula:
p = m × v
Where;
p = momentum (kgm/s)
m = mass (kg)
v = velocity (m/s)
According to this question, two students are running in a cross country race.
Student 1 has the following; m = 60kg, v = 7m/s
Student 2 has the following; m = 70kg, v = 7m/s
Using p = mv
Student 1, p = 60 × 7 = 420 kgm/s
Student 2, p = 70 × 7 = 490 kgm/s
From the result of the above calculations, student 2 with mass 70kg has more momentum.
What are 3 things that
happen to your body when you start exercising
regularly?
Explanation:
Weight loss and weight maintenance.
Muscle gain.
Improved mood.
Improved heart health.
_______ are events that disrupt the stability of a whole ecosystem.
A.Resources
B.Disturbances
C.Species
How many moles of oxygen are required to react with methanol in order to produce 13 moles of formaldehyde?
Answer:
6.5 moles of Oxygen are required
Explanation:
Based on the reaction:
CH3OH + 1/2 O2 → CH2O + H2O
1 mole of methanol reacts with 1/2 moles O2 to produce 1 mole of formaldehyde and 1 mole of water.
Thus, to produe 13 moles of formaldehyde, CH2O, are needed:
13 moles CH2O * (1/2mol O2 / 1mol CH2O) =
6.5 moles of Oxygen are requiredIdentifying Changes of Matter
Which of these are chemical changes in matter? Check all tha
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
what are the characteristics or properties that you can use to classify elements
Answer:
The number of outermost energy level electrons ( valency electrons )
The atomic number
Question 14 of 30
Which of the following elements has 1 valence electron?
The Periodic Table
A. Sodium (Na)
B. Chlorine (CI)
C. Calcium (Ca)
D. Helium (He)
SUBMIT
Answer:
A. Sodium (Na)
Explanation:
The total number of electrons in the outermost principal energy level of an element is called the valence electrons of that element.
Na (11)---→1s2 2s2 2p6 3s1
There 1 electron in the outermost principal energy level of Sodium. So, the number of valence electron of Sodium is 11.
Answer:
Na
Explanation:
I was learning about it recently, that dude's right, it's Sodium
why do objects cool down
Answer:
wla dyan ang sagut ehh baka mali yan
explain how ships made of steel float on water
Answer:
The air that is inside a ship is much less dense than water. That's what keeps it floating
Who made the first periodic table of the elements?
O A. Ernest Rutherford
O B. Dmitri Mendeleev
O C. Niels Bohr
O D. Henry Moseley
The periodic table was invented by Russian chemist Dmitri Mendeleev in 1869.
Answer:
B. Dmitri Mendeleev
Explanation:
Fill in the coefficients that will balance the following reaction:
Question 1 of 30
Why does atomic size increase as you go down a group on the periodic table?
A. Because the number of electron shells increases
B. Because there is more total attraction between electrons in the
shells and protons in the nucleus
C. Because the number of electron shells decreases
D. Because there is less total attraction between electrons in the
shells and protons in the nucleus
SUBMI
Answer:
Explanation:
Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.
How do protons and neutrons stay together in a nucleus?
A Electrostatic forces hold them together
B. Gravitational forces hold them together
C Weak nuclear forces hold them together
D. Strong nuclear forces hold them together
Answer:
strong nuclear forces that hold them together
Write the complete and net ionic equations for the following reactions. If only the reactants are given, predict the products and balance the equation first.
Explanation:
u can put them in order crossed are spectator ions. hope this helps:)
How many moles of H2O
moles of H2O are needed to produce 55.7 moles of H2?
Answer: 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given values:
Moles of [tex]H_2[/tex] = 55.7 moles
The chemical equation for the decomposition of water follows:
[tex]2H_2O\rightarrow 2H_2+O_2[/tex]
By the stoichiometry of the reaction:
If 2 moles of hydrogen gas is produced from 2 moles of water
So, 55.7 moles of hydrogen gas will be produced by = [tex]\frac{2}{2}\times 55.7=55.7mol[/tex] of water
Hence, 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]
Taking into account the reaction stoichiometry,
Reaction stoichiometryIn first place, the balanced reaction is:
2 H₂O → 2 H₂ + O₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
H₂O: 2 molesH₂: 2 molesO₂: 1 moleMoles of H₂O requiredThe following rule of three can be applied: if by reaction stoichiometry 2 moles of H₂ are produced from 2 moles of H₂O, 55.7 moles of H₂ are produced from how many moles of H₂O?
[tex]moles of H_{2} O=\frac{55.7 moles of H_{2}x 2 moles of H_{2} O}{2 moles of H_{2}}[/tex]
moles of H₂O= 55.7 moles
Finally, 55.7 moles of H₂O is requiredto produce 55.7 moles of H₂.
Learn more about the reaction stoichiometry:
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PLEASE HELP : Arrange the following elements into a food chain: plants, snake, Sun, hawk, and mouse.
Answer:
Plants ➯ Mouse ➯ Snake ➯ Hawk ➯ Sun
Explanation:
In Order As A Food Chain
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
What is element?A substance that could not be further decomposed according to any chemical reaction is known as a chemical element.
What is food chain?
The flow of nutrients as well as energy through such an ecosystem is described by a food chain. Energy is first produced by plants at the most fundamental level, and then it is used by higher-level species like herbivores. Energy is then transmitted from one carnivore to the next when they eat the herbivores.
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
To know more about food chain and element
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co2(g)+H20+148Kcal---->H2Co3 Endotérmica o exotérmica
endothermic
requires energy to occure
Which kind of energy is stored in the chemical bonds of molecules found in
wood?
A. Mechanical energy
B. Potential energy
C. Gravitational energy
D. Kinetic energy
Answer:
B. Potential energy
Explanation:
It's not mechanical energy, because it is not doing work
It's not kinetic energy because it;s not moving
It's not gravitational energy because it is not above the ground
It is potential energy because it is stored energy
WHAT IS THE STOCK NAME FOR FeSO^3
1. How many molecules of S2 gas are in 756.2 L?
a. 2.032 x 1025 molecules S,
b. 3.022 x 1023 molecules S,
c. 4.302 x 10 molecules S
d. 8.203 x 10' molecules S2
Answer: There are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.
Explanation:
It is known that 1 mole of any gas equals 22.4 L at STP. Hence, number of moles present in 756.2 L are calculated as follows.
[tex]Mole = \frac{Volume}{22.4 L}\\= \frac{756.2 L}{22.4 L}\\= 33.76 mol[/tex]
According to mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules.
Therefore, molecules of S present in 33.76 moles are calculated as follows.
[tex]1 mol = 6.022 \times 10^{23}\\33.76 mol = 33.76 \times 6.022 \times 10^{23}\\= 2.032 \times 10^{25}[/tex]
Thus, we can conclude that there are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.
How many liters of hydrogen (at 0.97atm and 24c) will produce 180 grams of water
I also need to know how to get the answer.
H₂ + ½O₂ → H₂O
2g → 18g
So, 18g water needs 2g H₂
So, 1g water needs 2/18g H₂
So, 180g water needs 2/18 x 180g H₂
→ 20 litres of H₂
Answer:
Explanation:
Molar mass of water, H2O = 2 + 16 = 18
So 180g of water contains 10M
H2 + O -> H2O
10M of Hydrogen is needed to produce 10M of water.
Molar volume at STP = 22.4L
So 10M of Hydrogen at STP = 224L
With Ideal Gas Law, P1V1/T1 = P2V2/T2
At STP, P1 = 1atm, T1=273K
At 0.97atm and 24c (273+24 = 297K), 10M of Hydrogen will take up:
1*224/273 = 0.97*V2/297
V2 = 224*297/273/0.97
= 251.23L
So the answer is 251.23L
Explain how monumentum conservation is applied in ball games
Answer:
Hi , your answer is that At impact, the cue ball stops, but transfers all of its momentum and kinetic energy to the other ball, resulting in the hit ball rolling with the initial speed of the cue ball. In an inelastic collision, momentum is conserved, but the total kinetic energy of the system is not conserved
Explanation:
i really hope i helped , pleae give me brainliest , have a nice day and thank you in advance :) .
the rows from left to right in the periodic table is called what
Answer:
The periodic table has rows that go left to right and columns that go up and down, just like any other grid. The rows are referred to as PERIODS, while the columns are referred to as GROUPS.
Explanation:
What happens to the freezing point of a solution when more solute is added?
Which of the following pairs of elements is most likely to form an ionic compound?
• magnesium and sodium
• nitrogen and sulfur
• oxygen and chlorine
• magnesium and chlorine
• carbon and fluorine
Explanation:
magnesium and sodium because they are minerals and part of iron
Predict the product(s) of the following neutralization reaction. Type the balanced the equation.
HNO3 + Ba(OH)2
Answer:
The products from the neutralization reaction are barium nitrate and water.
The balanced chemical equation is
2 [tex]HNO_{3}[/tex] + 1 [tex]Ba(OH)_{2}[/tex] --> 1 [tex]Ba(NO_3)_{2}[/tex] + 2 [tex]H_{2}O[/tex].
20 POINTS!!
What is the enthalpy of combustion when 1 mol C6H6(g) completely reacts with oxygen?
2C6H6(g) + 15O2(g) ? 12CO2(g) + 6H2O(g)
Options:
A. - 6339 kJ/mol
B. - 3169 kJ/mol
C. 1268 kJ/mol
D. 6339 KJ/mol
Answer:
-3169
Explanation:
trust the process
-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Explanation:
Given:
The reaction of combustion of [tex]C_6H_6(g)[/tex] along with enthalpies of formation of the compounds.
To find:
The enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Solution:
[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g)[/tex]
Enthalpy of the reaction:
[tex]\Delta H^o_{rxn}=\sum [\Delta H^o_{f,products}]-\sum [\Delta H^o_{f,reactants}]\\=[12mol\times \Delta H^o_{f.CO_2(g)}+6mol\times \Delta H^o_{f,H_2O(g)}]-[2 mol\times \Delta H^o_{f.C_6H_6(g)}+15\times \Delta H^o_{f,O_2(g)}]\\=[12mol\times (-393.50 kJ/mol)+6mol\times (-241.82 kJ/mol)]-[2mol\times 82.90kJ/mol+15mol\times 0 kJ/mol]\\=-6338.72 kJ[/tex]
[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g).\Delta H^o_{rxn}=-6338.72 kJ[/tex]
When 1 mole of [tex]C_6H_6(g)[/tex] reacts with oxygen gas:
[tex]=\frac{\Delta H^o_{rxn}}{\text{2 mol of } C_6H_6}\\=\frac{-6338.72 kJ}{2 mol}\\=-3169.36 kJ/mol\approx -3169 kJ/mol[/tex]
-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.
Learn more about enthalpy of combustion here:
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Explain why a mixture of copper (Il) Oxide and Magnesium reacts while there is no reaction when a mixture of Copper and Magnesium Oxide is heated.
Answer:
Copper oxide + magnesium = copper + magnesium oxide
Explanation:
When copper oxide is heated with magnesium powder, then magnesium oxide and copper are formed.. For example, magnesium is more reactive than copper. ... brown copper coats the surface of the magnesium.
