you administered 12g of samarium-153 to a patient. after roughly 6 days, how much is remaining? I NEED THE ANSWER ASAP

Explanation:

Both sodium and potassium belong to the same group. They both have only one electon in their outermost shell. But they belong to different periods. Sodium has 3 shells while potassium has 5. As the distance between the valence electron and the nucleus is more in potassium. It experience lesser pull by the nucleus and so can give away the valence electron very easily as compared to sodium which experience a greater pull from the nucleus. Thus potassium is more reactive. Reactivity increases on moving down the group.

Answer:

Sodium and potassium belongs to same group . Both has 1 electron to donate but sodium is less reactive because nuclear attraction makes it little bit difficult to loose electron as compared to potassium in which nuclear attraction becomes unable to pull the electrons towards itself . Hence we easily remove electron moreover due to screening effect also takes place .

Answer:

This is the answer

C-H, Br-H, F-H, LI-CI, Na-CI, K-F

Hope this helps.

Answer:

Strontium is the elements which can be found in this group as it is shiny, is solid in room temperature and has atoms with two valence electrons.

Answer: Scientists are working on nuclear fusion process. Nuclear fusion is the process in which two atomic nuclei combine to form another nuclei. In the process either energy is absorbed or released due to the difference in the mass of reactants and products.

Explanation:

Answer:

since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).

Sorry this take a little bit long. I was a little confused by the odd valence number

Answer:

Triads were groups of 3 elements with similar chemical and physical properties. Beryllium, magnesium, and calcium are all earth alkalis found in the earth

Explanation:

Answer:

The law of reciprocal proportions states that if two elements react individually with a given weight of a third element, the ratio of the masses with which they combine with the third element are either the same or a simple multiple of the ratio of the masses with which they combine with each other

The compounds formed includes;

1) Nitric oxide, NO

Nitrogen = 46.66% × 30.01 = 14

Oxygen = 53.34% × 30.01 = 16

2) Water, H₂O

Hydrogen = 11.21% × 18.01528 = 2

Oxygen = 88.79% × 18.01528 ≈ 16

3) Ammonia, NH₃

Hydrogen = 17.78% × 17.031 ≈ 3

Nitrogen = 82.22% × 17.031 ≈ 14

The ratio of nitrogen to oxygen in nitric oxide = 14:16 = 7:8

The ratio of nitrogen to hydrogen in ammonia = 14:3

The ratio in which hydrogen and oxygen combine with nitrogen = 3/16

The ratio of hydrogen and oxygen combine with each other in water = 2/16

Therefore, the ratio with which hydrogen and oxygen combine with nitrogen, is (2/3) times the ratio with which they combine with each other, which verifies the law of reciprocal proportions

Explanation:

The answer is zero also I suggest googling the questions there is a quizlet with the answers

Answer:

Divide the mass of the solute by the total volume of the solution. Write out the equation C = m/V, where m is the mass of the solute and V is the total volume of the solution. Plug in the values you found for the mass and volume, and divide them to find the concentration of your solution.

Answer:

[tex]\boxed {\boxed {\sf 8.38 \ L}}[/tex]

Explanation:

We are asked to find the new volume of a gas after a change in temperature. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]

The gas starts at 100 degrees Celsius and a volume of 33.5 liters. Substitute these values into the formula.

[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{T_2}[/tex]

The gas is cooled to 25 degrees Celsius, but the volume is unknown.

[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}[/tex]

We want to find the volume of the gas after it is cooled.  We must isolate the variable V₂. It is being divided by 25 degrees Celsius and the inverse of division is multiplication. Multiply both sides of the equation by 25 °C.

[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}* 25 \textdegree C[/tex]

[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}= V_2[/tex]

The units of degrees Celsius cancel.

[tex]25*\frac {33.5 \ L}{100 }= V_2[/tex]

[tex]8.375 \ L = V_2[/tex]

The original measurements have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 5 in the thousandths place tells us to round the 7 up to an 8.

[tex]8.38 \ L \approx V_2[/tex]

The new volume after the gas is cooled is approximately 8.38 liters.

Answer:

Gas

Explanation:

If you move a substance from one container to another and its volume changes, the substance is a gas. This is because, gases do not have fixed volume and shape; their shape and volume depend on the container used.

Answer:

I think gas.

Explanation:

Because gas doesn't have fixed shape and size.

Answer:

A). 2.1 × [tex]10^{-2}[/tex]

Explanation:

Given reaction,

2[tex]HF[/tex] (g) ⇄ [tex]H_{2}[/tex] (g) + [tex]F_{2}[/tex] (g)

The concentrations are as following;

[tex]HF[/tex] = 5.82 × [tex]10^{-2}[/tex] M

[tex]H_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M

[tex]F_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M

So,

[tex]K_{eq}[/tex] = [([tex]H_{2}[/tex] ) × ([tex]F_{2}[/tex])] ÷ [[tex]HF[/tex]]^2

Now,

We can determine the value of [tex]K_{eq}[/tex] by substituting the values in above formula:

[tex]K_{eq}[/tex] = [ (8.4 × [tex]10^{-3}[/tex] M) × (8.4 × [tex]10^{-3}[/tex] M)] ÷ [(5.82 × [tex]10^{-2}[/tex])^2

= 2.08 * [tex]10^{-2}[/tex]

=  2.1 × [tex]10^{-2}[/tex]

∵ [tex]K_{eq}[/tex] = 2.1 × [tex]10^{-2}[/tex]

Thus, option A is the correct answer.

Answer:

BHAI SECOND OPTION HOGA

Answer:b

Explanation:

Answer:

Initial temperature, T1 = 99.4 Kelvin

Explanation:

Given the following data;

To find the initial temperature (T1), we would use Charles' law;

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles' law is given by the formula;

[tex] \frac {V}{T} = K [/tex]

[tex] \frac {V_{1}}{T_{1}} = \frac {V_{2}}{T_{2}} [/tex]

Making T1 as the subject formula, we have;

[tex] T_{1} = \frac {V_{1}T_{2}}{V_{2}} [/tex]

Substituting the values into the formula, we have;

[tex] T_{1} = \frac {65.8 * 200}{132.4} [/tex]

[tex] T_{1} = \frac {13160}{132.4} [/tex]

Initial temperature, T1 = 99.4 Kelvin

Answer:

The Cavendish experiment, performed in 1797–1798 by English scientist Henry Cavendish, was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant

Explanation:

I think that's correct

Answer:

36.02g bbbbbbbbbbb hbbnjkkkj

Answer:

36.02g

Explanation:

Hope this helps!

Answer:

petroleum

Explanation:

usually found sedimentary rock.

definition: a liquid mixture of hydrocarbons that is present in certain rock strata and can be extracted and refined to produce fuels including gasoline, kerosene, and diesel oil, oil

Answer:

29.41% of Calcium and 47.04% of Oxygen

Explanation:

The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.

The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:

13.61g / 46.28g * 100 = 29.41% of Calcium

And percent composition of Oxygen is:

21.77g / 46.28g * 100 = 47.04% of Oxygen

Answer: 6 moles of [tex]KClO_3[/tex] will be decomposed.

Explanation:

We are given:

Moles of oxygen gas produced = 9 moles

The chemical equation for the decomposition of [tex]KClO_3[/tex] follows:

[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]

By the stoichiometry of the reaction:

If 3 moles of oxygen gas is produced by 2 moles of [tex]KClO_3[/tex]

So, 9 moles of oxygen gas will be produced by = [tex]\frac{2}{3}\times 9=6mol[/tex] of [tex]KClO_3[/tex]

Hence, 6 moles of [tex]KClO_3[/tex] will be decomposed.

Answer:

A water molecule is composed of two hydrogen atom and one oxygen atom but you can't simply take two hydrogen atom stick them onto an oxygen atom

Answer:

C

Explanation:

I hypothesis needs to be tested to know whether it is true or not. Here is the definition:

A supposition or proposed explanation made on the basis of *limited evidence as a started point for further investigation*

Answer:

The correct answer is - D. Freezing point depression.

Explanation:

When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.

Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.

While picking up a buret, an unknown solution left by a previous solution drips onto your hand - Gloves

While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor - Closed-toe shoes

While checking on a stirring solution, the solution splashes up towards your face - Goggles

While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench - Lab coat

Explanation:

So, according to the question. the matches will be:

While picking up a buret, an unknown solution left by a previous solution drips onto your hand - Gloves

While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor - Closed-toe shoes

While checking on a stirring solution, the solution splashes up towards your face - Goggles

While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench - Lab coat

Learn more about PPE here:

brainly.com/question/7991933?referrer=searchResults

brainly.com/question/18056380?referrer=searchResults

Answer:

i think A.

Explanation:

bc B. makes the molecules hight temp = move faster = more collisions = higher rate, C. it's use is to make reactions rates increase, D. somthung abt more surface area and easier collisions

1. Cl2 + H2O → HOCl + HCl

2. Tooth decay starts when when the pH of the mouth is lower than 5.5. Tooth enamel is made up of calcium phosphate and it is one of the hardest substances of the body. But it is corroded when the pH is less than 5.5. The bacteria of our mouth produce acids by degradation of sugar and food particles remaining in our mouth after eating food.

3. Fluorine salts are added in toothpaste to protect our teeth from tooth decay. Fluorine salts are mildly basic, so they neutrelise the acid in our mouth that leads to tooth decay.

4. Tincture of iodine is iodine, pottasium iodide and sodium iodide dissolved in ethanol. Iodine acts in an antiseptic manner by destroying microbial proteins and DNA.

5. Tincture of iodine is clear and reddish brown liquid.

Answer:

132.17amu

Explanation:

(14.01+1.01 multiplied by 4)=18.05×2=36.1

36.1+32.07= 68.17

16.00×4=64

68.17+64=132.17

Answer:

132.17 amu

Explanation:

just took the test. got 100

Answer:

1.Physical change

2. Chemical change

3. Heat

4.photosynthesis

5. composition

Answer:

A

Explanation:

The instrument in which the washer works as a valve is  A ; syringe

Each instrument listed have a washer and a valve, but of all the instruments listed above the instrument that its washer works also as a valve is the syringe.

A syringe is composed of a thin tube and a thinner hollow needle attached to the end of the thin tube. the needle is used and take in liquids and also expel liquids from the syringe ( i.e. washer and valve )

hence the instrument that its washer also functions as a valve is the syringe.

learn more about syringe : https://brainly.com/question/24283167