What is radioactive dating?
A. A comparison of the energy emitted from nuclei based on age
B. The determination of how old a radioactive isotope is
C. The use of radioisotopes to determine the age of something
D. A process to determine the half-life of a radioactive isotope

Answer:

A.0.20M

Explanation:

c 1 V 1 = c 2 V 2

Initial Volume, V1 = 200 mL

Final Volume, V2 = 200 + 400 = 600 mL

Initial Concentration, c1 = 0.60 M

Final Concentration, c2= ?

Solving for c2;

c2 = c1v1 / v2

c2 = 0.60 * 200 / 600

c2 = 0.20M

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)

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.

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

Stomatal pores in plants regulate the amount of water and solutes within them by opening and closing their guard cells using osmotic pressure. In order for plants to produce energy and maintain cellular function, their cells undergo the highly intricate process of photosynthesis .

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!

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

Answer:

Q = 219.07 J

Explanation:

Given that,

Mass of water, m = 15.4 g

The temperature changes from 22.2°C. to 25.6 °C.

The specific heat of water, c = 4.184 J/g °C

We need to find the heat needed to change in temperature. The formula is given by :

[tex]Q=mc\Delta T\\\\Q=15.4\times 4.184\times (25.6-22.2)\\\\Q=219.07\ J[/tex]

So, 219.07 J of heat is needed.

Answer:

Por cada 9 moles de zinc, 9 moles de fosfato de zinc se producen.

Explanation:

La reacción balanceada es:

3 Zn+ 2 H₂PO₄ → Zn₃(PO₄)₂ + 2 H₂

Por estequiometria de la reacción (es decir, la relación entre la cantidad de reactivos y productos en una reacción química), las siguientes cantidades de moles de cada compuesto participan de la reacción:

Entonces podes aplicar la siguiente regla de tres: si por estequiometria 3 moles de zinc produce 1 mol de fosfato de zinc, 9 moles de zinc cuántos moles de fosfato de zinc producirá?

[tex]moles de fosfato de zinc=\frac{9 moles de zinc*1 mole de fosfato de zinc}{3 moles de zinc}[/tex]

moles de fosfato de zinc= 9

Por cada 9 moles de zinc, 9 moles de fosfato de zinc se producen.

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

Answer:

4th one

Explanation:

a physical change is something u can see, so if the substance changes its properties then thats a physical change.

Answer:

C. 3

Explanation:

volume = length×width×height

3×3×3=27

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!

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:

Answer:

Because Disaccharides have more chemical bonds.

Explanation:

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.

Answer:

okay you need to find the synnomy

Answer:4.5 ×10^22)

Explanation:

no. of particles =no. of mole×avogadro's number of particles no. of particles =0.75×6.02×10^23 no. of particles =4.5 ×10^22

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:

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.

Answer:

D: False

E: Ethane

Explanation:

Answer: Calcium ion Ca² : 1 s² 2s² 2p ^6 (sorry I don't get 6 similar way as 2) 3s² 3p^6

Also 18 electrons, because Calcium donates two 4s electrons

Explanation:

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

Answer: 2400 km

Explanation: 1200 km/hr • 2 hr = 2400 km

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.

Answer: question 2 is (a) (25+273)k=298k(b) (373+273)k=646k

question 5 is 25 degree Celsius

question 1 is

a = (293-273) =20 degree Celsius

b = (470-273)=197 degree Celsius

question 3 is

a = naphthalene ball undergo sublimation due to which it convert directly into vapour and disappear into air without leaving any solid

b = the participle of perfume diffuse rapidly into air and its smell can be felt while sitting serval metre away

question 4 isthe force of allraction between the particles increases as we go from liquid to gas so the required order is : Oxygen< water< sugar

I hope it is helpful to you

Answer: I’m pretty sure your answer is B

Explanation:

Answer:

The answers is B

Explanation:

I did that question before !!

Answer:

chemical weathering

physical weathering

biological weathering

Explanation:

biological weathering it when the plants grow the root move into the rocks to cause break down