Answer:
There were originally 8 atoms of Potassium-40.
Explanation:
The half-life of a radioactive material is the time taken for half the original material to decay or the time required for a quantity of the radioactive substance to reduce to half of its initial value.
If the original material formed without any Argon-40, it means that the atoms originally present were Potassium-40 atoms.
Presently, there are 7 Argon-40 atoms for every 1 of Potassium-40, we can deduce the number of half-lifes the Potassium-40 has undergone as follows :
After one half-life, (1/2) there will be one Potassium-40 atom for every Argon-40 atom.
After a second half life, 1/2 × 1/2 = 1/4: there will be one Potassium-40 atom for every three atoms of Argon-40.
After a third half-life, 1/4 × 1/2 = 1/8: there will be one Potassium-40 atom for every 7 atoms of Argon-40.
Since there are 1/8 atoms of Potassium-40 presently, there were originally 8 atoms of Potassium-40.
i need help with d and e
Answer:
D: False
E: Ethane
Explanation:
Where have you seen evidence of viscosity?
Answer:
Lubrication in vehicles. When you put oil into your car or truck, you should be aware of its viscosity
Cooking. Viscosity plays a significant role in the preparation and serving of food.
Manufacturing. Manufacturing equipment requires appropriate lubrication to run smoothly.
oh, and medicine
how are fossils fuels differ than fossils
Answer:
fossils are like bones of dinosaurs and other animals. fossil fuels are non renewable sources like natural gas, coal, and nuclear energy. (there is more than those)
Explanation:
Molar Mass:
Find the molar masses of the following compounds. Also report the number of atoms in the compound:
1) NaBr
2) PbSO4
3) Ca(OH)2
4) Na3PO4
5) (NH4)2CO3
6) C6H12O6
7) Fe3(PO4)2
8) (NH4)2S
9) Zn(C2H3O2)2
10) AgF
Answer:
Atomic models are important because, they help us visualize the interior of atoms and molecules, and thereby predicting properties of matter.
Explanation:
We study the various atomic models in our course of study because, it is important for us to know, how did people come to the present concept of an atom. How did physics evolve from classical to quantum physics.
All these are important for us to know and thus, knowledge about various atomic models, their discoveries and drawbacks and finally improvements based on scientific evidence present at that time is important for us to understand the underlying theory very well.
Explanation:
A DAY IN THE LIFE OF METIS JOURNAL. I WROTE IT HOPE U LIKE IT XD
We, who live in the west, were Nomadic. So we always moved from place to place to hunt buffalo and other fur-bearing animals. And now again we have to shift everything we collected , like, all the essential needs we collected. It’s really hard to shift stuff, But when you move to a new place you get to see new beautiful places. They are just so satisfying to see! It’s like all my work(like the shifting work) is paid off. I love it! We always meet the Hudson’s bay company employees, and give them furs which we took from the bissons and other furry animals we hunted. And in exchange they give us their (Hudson’s Bay company) goods. Which is good! Because then we or I won't be able to enjoy that delicious pemmican!
The one reason that makes me proud of my parents is that because of them I am like a translator for both sides in the fur trade! Anyways coming back to the present. As I said before, we were moving today to another place, But on the way some people along with my father will ride the famous York boats carrying supplies to fur posts. I begged my father to take me with him! And as usual he gave me some silly reason for me to stay. And now since I don’t have anything to do I will-..Nevermind, My mom’s calling me. Okay after helping my mom keep the fur posts into the York boats me , my mom, and the others are just relaxing and enjoying nature just to take a break. Since, I am so obsessed with my Journal notebook today I’m just going to sit here and right what comes to my mind. I’m not like the others who always seem to be talking with someone. I like my own space!
I kind of miss my dad already, but he and his fellow members need to travel the waterways from the red river further west and north to hudson bay. These red river carts also travel the trek back and forth over land to St. Paul, Minnesota and to posts in saskatchewan. Speaking about the red river, the only large settlement in the region is the red colony. About 12000 people lived in this colony around Fort Garry. Some were the original Selkirk settlers or their descendents. They had come from Scotland with lord Selkirk when he established the colony in 1811. Many of these original settlers were poor farmers who had been displaced from their lands in scotland. They had endured many hardships in the early years of settlement, including foods, hunger, and sickness. I love studying about other colonies, cultures , history etc.
Why would the same amount of gas be produced even if we increase the amount of baking soda?
Answer:
Explanation:
If you are not increasing the amount of vinegar, the adding more baking soda has nothing to react with. The limiting reagent is vinegar (or some other acid).
The usual reaction is
HC2H3O2 + NaHCO3 ===> NaC2H3O2 + HOH + CO2 which is the gas being expelled.
If you increase the NaHCO3 nothing more will happen until you increase the vinegar.
Ba(NO3)2 + 2LiOH → Ba(OH)2 + 2LiNO3
How many nitrate ions are in the products and the reactants of the chemical equation?
A.
one in the reactants and two in the products
B.
three in the reactants and three in the products
C.
two in the reactants and two in the products
D.
six in the reactants and three in the products
Answer:
C.
two in the reactants and two in the products
Explanation:
The law of conservation of mass helps us balance chemical equations so that there are the same number and type of atoms in the reactants and products.
There are two nitrate ions in Ba(NO3)2 and two in 2LiNO3.
two different people run a race the graphs track their distance vs. times during the race. Explain the difference between the two runners motions. use words like speed and acceleration.
Answer:
Runner A is moving at a constant speed, therefore has a positive acceleration.
Runner B is moving at a constant speed, stopping, then speeding up again.
Explanation:
A mixture of helium, nitrogen and oxygen has a total pressure of 781 mmHg. The partial pressure of helium is 331 mmHg, and the partial pressure of nitrogen is 222 mmHg. What is the partial pressure (in mmHg) of oxygen in the mixture?
Answer:
Partial pressure of O₂ = 228 mmHg
Explanation:
The mixture is made of three gases, He, N₂ and O₂.
Total pressure of it, is 781 mmHg.
There is a law from gases, that indicates the sum of partial pressures of each gas in a mixture will be the total pressure of the system. In conclussion:
Partial pressure of He + Partial pressure of N₂ + Partial pressure of O₂ = Total pressure.
331 mmHg + 222 mmHg + Partial pressure of O₂ = 781 mmHg.
Partial pressure of O₂ = 781 mmHg - 331 mmHg - 222 mmHg
Partial pressure of O₂ = 228 mmHg
True or False? You can observe physical properties of matter without changing the identity of the substance
2. What happens to the temperature of air when it is compressed?
Explanation:
the pressure and temperature of the air increase
reason:
the volume of the space containing air decreases.
Explanation:
Whether you know it or not, compressed air is involved in every aspect of our lives, from the balloons at your birthday party to the air in the tires of our cars and bicycles. It was probably even used when making the phone, tablet or computer you’re viewing this on.
The main ingredient of compressed air is - you guessed it! - air. Air is a gas mixture, which means it consists of many different gases. Primarily these are nitrogen (78%) and oxygen (21%).
The temperature of the air is directly proportional to the mean kinetic energy of these molecules. This means that the air temperature will be high if the mean kinetic energy is large (and the air molecules move faster). The temperature will be low when the kinetic energy is small.
Compressing the air makes the molecules move more rapidly, which increases the temperature. This phenomenon is called “heat of compression”. Compressing air is literally to force it into a smaller space and as a result bringing the molecules closer to each other. The energy that gets released when doing this is equal to the energy required to force the air into the smaller space. In other words, it stores the energy for future use.
I’ll really appreciate it if you help me out with these 2 questions .
What is the correct formula for the missing product from the equation below:
Na2CO3(aq)
+
CaCl2 (aq)
> NaCl +
Answer:
CaCO3 (s)
Explanation:
This equation is a double replacement equation, which means that since Na and Cl and paired, Ca and CO3 will be paired.
Then, you look at the charge of each element and balance
Ca has a 2+ charge
CO3 has a 2- charge
The 2+ charge and the 2- charge will cancel so there is no need for a subscript or to balance the equation
The complete equation will be Na2CO3 (aq) + CaCl2(aq) -> NaCl (aq) + CaCO3 (s)
I hope this helps and have a great day!
What is the molality of a solution containing 18.2 g HCl and 250. g of water?
(EZ Points here)
Answer:
1.99M
Explanation:
Molality can be calculated by dividing the moles of solute by the mass of the solvent i.e.
Molality (M) = n of solute (mol) ÷ mass of solvent (kg)
Based on the information, mass of HCl (solute) = 18.2g, mass of solvent (water) = 250.0g
mole of solute = mass/molar mass
Molar mass of HCl = 1 + 35.5 = 36.5g/lol
mole = 18.2/36.5
mole = 0.499mol
Mass of solvent = 250.0g
In Kg, mass of water = 250/1000
= 0.250Kg
Molality = 0.499/0.250
Molality = 1.996
Molality of the solution = 1.99M
In a reaction 25.00mL of nitric acid required 51.4mL of 0.73M calcium hydroxide. Calculate the grams of nitric acid per liter of solution
Answer:
47.27 g HNO₃
Explanation:
The reaction between nitric acid (HNO₃) and calcium hydroxide (Ca(OH)₂) is the following:
2HNO₃(aq) + Ca(OH)₂(aq) → Ca(NO₃)₂ + 2H₂O(l)
According to the chemical equation, 2 moles of HNO₃ reacts with 1 mol of Ca(OH)₂. At the point of total neutralization, the total number of moles of HNO₃ reacts with the total number of moles of Ca(OH)₂:
2 x moles HNO₃ = moles Ca(OH)₂
The number of moles is equal to the product of molarity of the solution (M) and the volume in liters (V):
M(HNO₃) = ?
M(Ca(OH)₂) = 0.73 M
V(HNO₃) = 25.00 mL x 1 L/1000 mL = 0.025 L
V(Ca(OH)₂) = 51.4 mL x 1 L/1000 mL = 0.0514 L
So, we can write the equation at neutralization point as:
2 x (M(HNO₃) x V(HNO₃)) = M(Ca(OH)₂) x V(Ca(OH)₂)
From this, we can calculate the molarity of HNO₃:
M(HNO₃) = (M(Ca(OH)₂) x V(Ca(OH)₂))/2 x V(HNO₃)
= (0.73 M x 0.0514 L)/(2 x 0.025 L)
= 0.75 M HNO₃
We can convert the molarity from M (mol/L) to g/L by using the molecular weight of HNO₃:
Mw(HNO₃) = 1 g/mol H + 14 g/mol N + (3 x 16 g/mol O) = 63 g/mol
Finally, we multiply the molarity by the molecular weight to obtain the grams of nitric acid per liter of solution:
0.75 mol/L HNO₃ x 63 g/mol = 47.27 g HNO₃
What is the percent water in the compound CaCl2 2H2O ?
Answer:
147.1g
Explanation:
7) Which of the following has the most nonpolar bond?
A. HAS
B. HCl
C. Brz
D. OF2
What does each letter mean in the acronym pufart mean
Answer:
The acronym is used to remember evidence of a chemical change.
Explanation:
P=precipitate
U=unexpected color change
F=fizzing
A=aroma
R=replaced by a new substance
T= temperature change
can someone answer this
Answer:
choice B
58Fe^2+
Explanation:
hope this helped
ill give brainlist pls help me and don't guess I want full explanation please.
Answer:
C. 3
Explanation:
volume = length×width×height
3×3×3=27
Why do the more complex sugar disaccharides store more energy than
monosaccharides?
Answer:
Because Disaccharides have more chemical bonds.
Explanation:
what chemical is 2:8:6 in electrons?
At which type of tectonic plate boundary is a volcano least likely to occur?
Answer: the answer is a
Explanation:
I took the test and got it wrong because someone said the answer was divergent boundary and it’s wrong. I hate them I hate them I hate them. I hate it I hate school
Transform boundary is the type of tectonic plate boundary is a volcano least likely to occur.
What is meant by Transform boundary?A transform fault or transform boundary, sometimes called a strike-slip boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone.Transform boundary is the type of tectonic plate boundary is a volcano least likely to occur.
To learn more about Transform boundary refer:https://brainly.com/question/18190655
#SPJ2
Compare the Atomic Radius of Lithium (Li) and
Potassium (K) and EXPLAIN.
Answer:
Lithium has a smaller atomic radius than potassium
Explanation:
Lithium has fewer electrons therefore fewer orbitals (1s2, 2s1) vs Potassium with more electron and therefore orbitals (1s2, 2s2, 2p6, 3s2, 3p6, 4s1)
Help ASAP If you know what to do comment if u don’t I’ll report you ! Points added
Proton:
Positive
Found in Nucleus
Mass of 1 AMU
Neutron:
Neutral
Found in Nucleus
Mass of 1 AMU
Electron:
Negative
Found in orbitals
Mass of 0 AMU
2KCIO3 -> 2KCI+ 302
How many moles of oxygen are produced by
the decomposition of 6.0 moles of potassium
chlorate, KCIO3?
Answer:
9 moles
Explanation:
The balanced chemical equation for this decomposition reaction is as follows:
2KCIO3 → 2KCI+ 302
Based on this equation, 2 moles of potassium chlorate (KCIO3) decomposes to form 3 moles of oxygen gas (O2).
Hence, 6 moles of pottasium chlorate will decompose to produce;
6 × 3 ÷ 2
= 18 ÷ 2
= 9 moles of O2.
Science plz help due soon 6th grade Major grade
Answer:
the answer is d.
Explanation:
because the core is deepest then is the mantle and the lithpsphere is last .
I put a picture incase you need a visual example.
31. Solve this Gibbs' Free Energy Equation:
For a reaction at 200 K, the Delta H has a value of 250 kJ and the Delta S has a value of 0.100 kJ. 1s
the reaction spontaneous or not spontaneous?
Answer:The standard Gibbs energy change at 300K for the reaction 2A⇔B+C is 2494.
Explanation:
ΔG = free energy at any moment.
ΔGo = standard-state free energy.
R is the ideal gas constant = 8.314 J/mol-K.
T is the absolute temperature (Kelvin)
lnQ is natural logarithm of the reaction quotient
What is the experimental yield of Li2O?
The value of Kp for the reaction 2 A(g) + B(g) + 3 C(g) → 2 D(g) + E(g) is 18530 at a particular temperature. What would be the value of Kp for the reaction 2 D(g) + E(g) → 2 A(g) + B(g) + 3 C(g)?
Answer:
[tex]Kp2=5.3967x10^{-5}[/tex]
Explanation:
Hello there!
In this case, since the Kp for the first reaction is given, according to the following equilibrium expression:
[tex]Kp=\frac{p_D^2p_E}{p_A^2p_Bp_C^3} =18530[/tex]
However, since the second reaction stands for the reverse of the initial one, the equilibrium expression would be:
[tex]Kp_2=Kp=\frac{p_A^2p_Bp_C^3}{p_D^2p_E}[/tex]
And therefore its Kp the inverse of the aforementioned one:
[tex]Kp2=1/18530\\\\Kp2=5.3967x10^{-5}[/tex]
Best regards!
Draw the correct Lewis structure of this molecule by placing atoms on the canvas and connecting them with bonds. Include all hydrogen atoms and lone pairs of electrons.
Answer:
hello your question is incomplete attached below is the complete question
answer : attached below
Explanation:
The Lewis structure given in the question is incorrect attached below is the correct Lewis structure.
Lewis structure of a molecule is the representation of the valence electrons in a molecule