Answer: yes I can do that tomorrow
Explanation:
A sample of radioactive material starts with 80 grams. After 3 half-lives have passed, how much radioactive sample remains?
Answer:
After 3 half lives 10 g of radio active material left.
Explanation:
Given data:
Total amount of radio active material = 80 g
Amount left after 3 half lives = ?
Solution:
At time zero = 80 g
At first half life = 80 g/2 = 40 g
At 2nd half life = 40 g/2 = 20 g
At 3rd half life = 20 g/2 = 10 g
Thus, after 3 half lives 10 g of radio active material left.
A solution has a pH of 11.75. Calculate the [H:0*] of the solution
The [H₃0⁺] of the solution : 1.778 x 10⁻¹² M
Further explanationpH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH of solution = 11.75
the [H₃0⁺] of the solution :
[tex]\tt pH=-log[H_3O^+]\\\\11.75=-log[H_3O^+]\\\\(H_3O^+]=10^{-11.75}=1.778\times 10^{-12}[/tex]
Please help me!!!!
Use the activity series to determine if the following will react.
HCI + Zn —>
State whether they will or won't react and explain your reasoning.
Answer:
1. They will react.
2. 2HCI + Zn —> ZnCl2 + H2
Explanation:
1. From the question given above,
We can see that Zn is higher than H in the activity series.
NOTE: Elements higher (i.e at the top) in the activity series will displace those lower (i.e at the bottom) in the series. Thus, Zn is higher in the series than H. Therefore, Zn will displace H from solution. Hence, they will react.
2. The product obtained from the reaction can be seen as follow:
HCI + Zn —> ZnCl2 + H2
The above equation can be balance as follow:
There are 2 atoms of H on the right side and 1 atom on the left side. It can be balance by putting 2 in front of HCl as shown below:
2HCI + Zn —> ZnCl2 + H2
. If you have 4.65 moles of H2 gas from: 2H2 + O2 → 2H2O
a. How much Oxygen is needed to completely react with hydrogen?
O2? =
b. How many moles of water will be produced?
H2O? =
What is the density of an object that has a mass of 350 g and a volume of 95 cm3?
A)
36.8 g/cm3
B)
3.68 g/cm3
33,250 g/cm3
D)
27-g/em3
Answer:
3.68 g/cm3
Explanation:
D = M / V
350 / 95
someone please help me answer this i’m struggling and i will give branliest
Answer:
bottom right corner with arrows going up
What term is used when heat is transferred from one piece of matter to another until they are of equal temperature?
thermal contact
When heat flows from one object or substance to another it is in contact with, the objects or substances are said to be in thermal contact. The state where objects in thermal contact with each other reach the same temperature, no heat flows between them.
Pls help plssssssdsss
Answer:
i do k12 too!
Explanation:
lol
Which characteristic could distinguish a crystalline solid from an amorphous
solid?
A. Molecular mass
B. The way it breaks
C. Hardness
D. Color
The characteristic that could distinguish a crystalline solid from an amorphous solid is option b. The way it breaks.
Difference between the crystalline solid and amorphous solid:Crystalline solids contained edges and faces, that should be diffracted x-rays, and have sharp melting points.
While on the other hand, amorphous solids should contain irregular does not provide well-resolved x-ray diffraction patterns.
hence, the option b is correct.
And, the rest of the options are wrong.
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A compound is found to consist of 34.5% sodium, 16.4% boron, and 48.6% oxygen. What is the empirical formula?
A. NaBO3
B. NaBO2
C. Na2B4O7
D. Na3BO3
Answer: The empirical formula is [tex]NaBO_2[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given:
Mass of Na= 34.5 g
Mass of B= 16.4 g
Mass of O = 48.6 g
Step 1 : convert given masses into moles.
Moles of Na =[tex]\frac{\text{ given mass of Na}}{\text{ molar mass of Na}}= \frac{34.5g}{23g/mole}=1.5moles[/tex]
Moles of B =[tex]\frac{\text{ given mass of B}}{\text{ molar mass of B}}= \frac{16.4g}{11g/mole}=1.5moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{48.6g}{16g/mole}=3moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Na = [tex]\frac{1.5}{1.5}=1[/tex]
For B = [tex]\frac{1.5}{1.5}=1[/tex]
For O =[tex]\frac{3}{1.5}=2[/tex]
The ratio of Na: B: O= 1: 1: 2
Hence the empirical formula is [tex]NaBO_2[/tex]
In a 0.25 M solution of HA (a weak acid), 1.0 % if the HA is ionised.
a) Calculate the actual concentration of HA, H₂O ^+ and A^- in this solution ?
Answer:
dunno
Explanation:
9. If purple flowers are dominant to white flowers and
two white flowered plants are crossed, what
percentage of their offspring will be white
flowered?
What is question?
Work shown would be appreciated ❤️
20 points!!!!
Answer:
35.453 amu.
Explanation:
From the question given above, the following data were obtained:
Isotope A (Cl–35):
Abundance (A%) = 75.77%
Mass of A = 34.969 amu
Isotope B (Cl–37):
Abundance (B%) = 24.23%
Mass of B = 36.966 amu
AVERAGE atomic mass of Cl =?
The average atomic mass of Cl can be obtained as follow:
Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]
Average = [(34.969 × 75.77)/100] + [(36.966 × 24.23)/100]
Average = 26.496 + 8.957
Average atomic mass of Cl = 35.453 amu.
What happens after condensation to cause precipitation?
A
The sun heats water on the Earth's surface.
B
Water is absorbed into the ground.
C
Clouds fill with moisture and get too heavy.
D
Excess water runs downhill.
Answer:
The answer is c, Clouds fill with moisture and get too hravy
PLEASE HELP I DONT WANT TO FAIL!! ):
Cesium Bromide and Strontium Nitrate react to form Strontium Bromide and Cesium Nitrate.
a. Write out the word equation representing this reaction
b. Write out the skeletal equation representing this reaction
c. Write out the balanced equation representing this reaction
what is the molarity of a solution made by adding 0.720 mole of NaOH to 2.40 liters of water
Answer:
Molarity = 0.3 M
Explanation:
Given data:
Moles of NaOH = 0.720 mol
Volume of water = 2.40 L
Molarity = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Molarity = 0.720 mol / 2.40 L
Molarity = 0.3 mol/L
Molarity = 0.3 M
for the following equation to be bal
Answer:
What's the rest of the question
Explanation:
The radius of the moon is approximately 1,350,000m. What is the radius in miles ( 1 mile= 1600m)
Answer:
843.75
Explanation:
ok so the moon radius is 1,350,000meters right so meters to miles
1 mile=1600meters
1,350,000/1600=843.75
843.75 miles
Hope that helps!
Merry Christmas!
THE OH BOND IN WATER IS POLAR BECAUSE
Answer: In the case of water, we know that the O-H covalent bond is polar, due to the different electronegativities of hydrogen and oxygen. Since there are two O-H bonds in water, their bond dipoles will interact and may result in a molecular dipole which can be measured.
Explanation:
1 carbon atom mixed with 1 oxygen atom what is the formula
Answer:
carbon mono oxide CO
Explanation:
as both are in 1:1 ratio so CO is formed
Write the formula for diphosphorous pentoxide
Answer:
P4O10
Explanation:
Protons and neutrons are similar because they both:
cause objects to become charged
are attracted to electrons
are found in the nucleus of an atom
have positive charges
Answer:
C. are found in the nucleus of an atom
Explanation:
Protons and Neutrons are always located at the center of the atom also called as the nuclei of the atom and constitute nearly all the mass of the atom, while the electrons revolve around them in orbits called shells. Only protons have a positive charge and electrons have negative charges, due to which only protons and electrons attract each other, while neutrons lack charges or have 'Neutral Charges'.
#1...TRUE/FALSE, the best way to write a conclusion is to use the RERUN method.?
#2...TRUE/FALSE, an example of an inference is “I saw it rain today.”?
#3...TRUE/FALSE, an example of a quantitative observation is “That is a red doll.”?
#4...TRUE/FALSE, a scientific hypothesis is written as “If [independent variable] Then [dependent variable.]”?
please answer all of them
How many joules are required to melt 250 grams of water
Answer:
i not sure but i searched it up and it said Q=104525J
Explanation:
What mass of dinitrogen monoxide, N2O, contains the same number of molecules as 3.00 g of trichlorofluoromethane, CCl3F?
Answer:
0.9612 g
Explanation:
First we calculate how many moles are there in 3.00 g of CCl₃F, using its molar mass:
3.00 g CCl₃F ÷ 137.37 g/mol = 0.0218 mol CCl₃FNow, we need to calculate how many grams of N₂O would have that same number of molecules, or in other words, the same amount of moles.
Thus we calculate how many grams would 0.0218 moles of N₂O weigh, using the molar mass of N₂O :
0.0218 mol N₂O * 44.013 g/mol = 0.9612 g N₂OThe mass of dinitrogen monoxide is 0.9612 g
The calculation is as follows:The number of moles are there in 3.00 g of CCl₃F, using its molar mass:
= 3.00 g CCl₃F ÷ 137.37 g/mol
= 0.0218 mol CCl₃F
Now the mass should be
=[ 0.0218 mol N₂O × 44.013 g/mol
= 0.9612 g N₂O
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S this true or false most energy we use comes from fossil fuels
Answer:
True. Hope this helps. :)
A gas sample occupies 4.39 L at 44 ºC. What will be the new volume, using Charles’ Law, if the temperature decreases to 25 ºC?
Hi there! :)
[tex]\large\boxed{x = 2.49 L}[/tex]
Use the proportion for Charles' Law where:
[tex]\frac{v_{1}}{t_{1}}= \frac{v_{2}}{t_{2}}[/tex]
v1 = initial volume
t1 = initial temperature
v2 = final volume
v2 = final temperature
Substitute in the given values into the proportion:
v1 = 4.39 L
t1 = 44° C
t2 = 25°C
v2 = x L
Set up the proportion:
[tex]\frac{4.39}{44} = \frac{x}{25}[/tex]
Cross multiply:
[tex]25 * 4.39 = 44x\\\\109.75 = 44x\\\\x = 2.49 L[/tex]
Answer:
The new volume will be approximately 2.49 L.
Explanation:
We are given that a gas sample occupies 4.39 L at 44° C.
We are also given that we are going decrease the temperature to 25° C.
Charles' Law has a formula which shows the relationship between the volumes of a samples and the temperatures of the samples.
The proportion is shown as:
[tex]\displaystyle \bullet \ \ \ \frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex],
where V₁ and V₂ are the initial and final volume respectively and T₁ and T₂ are the initial and final temperature respectively.
This proportion can be used to determine what our unknown is. We need to know the final volume.
[tex]\displaystyle \frac{4.39 \ \text{L}}{44 \ \text{C}} = \frac{\text{x}}{25 \ \text{C}}\\\\\\\frac{4.39}{44} = \frac{x}{25}\\\\\\4.39 \times 25 = 44 \times x\\\\\\44x = 109.75\\\\\\\frac{44x}{44}=\frac{109.75}{44}\\\\\\x = 2.49432 \approx \boxed{2.49 \ \text{L}}[/tex]
Therefore, if we reduce the temperature to 25 °C, we will be reducing the volume of the substance to 2.49 L.
What mass (in grams) of silver contains the same number of atoms as 5.59 grams of sulfur?
Answer:
18.84 g of silver.
Explanation:
We'll begin by calculating the number atoms present in 5.59 g of sulphur. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of sulphur contains 6.02×10²³ atoms.
1 mole of sulphur = 32 g
Thus,
32 g of sulphur contains 6.02×10²³ atoms.
Therefore, 5.59 g of sulphur will contain = (5.59 × 6.02×10²³) / 32 = 1.05×10²³ atoms.
From the calculations made above, 5.59 g of sulphur contains 1.05×10²³ atoms.
Finally, we shall determine the mass of silver that contains 1.05×10²³ atoms.
This is illustrated below:
1 mole of silver = 6.02×10²³ atoms.
1 mole of silver = 108 g
108 g of silver contains 6.02×10²³ atoms.
Therefore, Xg of silver will contain 1.05×10²³ atoms i.e
Xg of silver = (108 × 1.05×10²³)/6.02×10²³
Xg of silver = 18.84 g
Thus, 18.84 g of silver contains the same number of atoms (i.e 1.05×10²³ atoms) as 5.59 g of sulfur
Which statement correctly describe the nucleus of the atom
Protons,neutrons,electrons
The Earth and the spaceship both have mass. The astronaut is attracted to Earth by gravity, but he is not attracted to the spaceship. Explain.