THIS ANSWER CORRECT?

Answer:

The half-life of a radioisotope describes the amount of time it takes for said isotope to decay to one-half the original amount present in the sample.

Nitrogen-13, because it has a half-life of ten minutes, will experience two half-lives over the course of the twenty minute period. This means that 25% of the isotope will remain after this.

0.25 x 128mg = 32mg

32mg of Nitrogen-13 will remain after 20 minutes.

Answer:54,6

Explanation:

Answer:

yes it is 54,6

Explanation:

54,6 you ar correct you did a graet job

Answer:3

Explanation:

I added and substituted for the garlic

Answer:

the sun and moon are aligned with the earth.

Answer:

uhhh first or third quarter

Explanation:

0.10 mol H₃PO₄

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

6.3 × 10²² molecules H₃PO₄

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

0.104616 mol H₃PO₄ ≈ 0.10 mol H₃PO₄

Answer:

608 g

Explanation:

Mass of flask + contents = 489.1 g

Mass of flask = 241.3 g.

Mass of water = 489.1 - 241.3 = 247.8 g

Density of water = 1.0 g/cm^3

volume of water = 247.8 g/1.0 g/cm^3

Volume = 247.8 cm^3

But

Volume of flask = volume of water

Volume of flask = 247.8 cm^3

volume of chloroform = volume of flask

mass of chloroform = 1.48 g/cm^3× 247.8 cm^3

Mass of flask + chloroform = 366.7 g + 241.3 = 608 g

The expression of Boyle's law is to be considered as the PV=constant.

Hence, the option d is correct.

In physics, the volume of the gas at a similar kind of temperature should changed oppositely along with the pressure that should be exterted on it.

Also, the expression be like

P1V1 = P2V2

hence, The expression of Boyle's law is to be considered as the PV=constant.

Hence, the option d is correct.

learn more about law here: https://brainly.com/question/14696622

The question is incomplete, the complete question is shown in the image attached to this answer

Answer:

Most similar - sulphur

least similar- gallium

Explanation:

The compound formed when hydrogen reacts with oxygen is water. The chemical formula of water is H2O.

Water is very similar to H2S which is the compound formed when hydrogen reacts with sulphur. The bonds in water and H2S are both polar covalent bonds.

However, gallium is a metal and its hydride (GaH3) is least similar to water.

Answer:

Volcanoes can produce oxygen in the atmosphere.

Explanation:

Answer:

See explanation and image attached

Explanation:

A poly atomic ion refers to an ion that has more than one atom. The nitrate ion is one of such! It contains three oxygen atoms and one nitrogen atom.

It is an ion in which there is charge separation as shown in the image attached to this answer. The structures shown are the Lewis structure of the nitrate ion that satisfy the octet rule.

Answer:

then it only gotta be 2 other options .

Explanation:

Answer:

after 45 days 9 g left

Explanation:

Given data:

Half life Na-24 = 15 days

Mass of sample = 72 g

Mass remain after 45 days = ?

Solution:

Number of half lives passed:

Number of half lives = time elapsed / half life

Number of half lives = 45 days / 15 days

Number of half lives = 3

At time zero total amount = 72 g

After first half life = 72 g/ 2= 36 g

At 2nd half life = 36 g/2 = 18 g

At 3rd half life = 18 g/2 = 9 g

Thus after 45 days 9 g left.

Hey there!

The formula for density is d = m/v.

The mass of the sample is 56.5 g, and the volume of the sample is 5 cm³.

So, to plug these values into the equation, we have:

[tex]d=\frac{56.5}{5}[/tex]

Simplified, this is:

d = 11.3

The unit for this is g/cm³, or grams per cubic centimeter.

So, the density of lead is 11.3 g/cm³.

Hope this helps!

Answer:

11.3 g/cm³

Explanation:

Density of lead

= Mass / Volume

= (56.5 g) / (5 cm³)

= 11.3 g/cm³

Answer:

an insulator is a substance that does not readily allow the passage of heat or sound.

Explanation:

The answer to the question is a. Passage I contains a character study, but Passage 2 focuses more on concepts.

for all who were wondering

Answer:

all of the above

Explanation:

Answer:

Disease ranching

Explanation:

Floods and Droughts are caused by the enviorment. Diseases are but a product and don't  affect the enviorment.

Answer:

disease ranching is not a natural change to the environment .

Explanation:

This all happen because of human activities

Answer:

The answer to this question would be:  

2. The exponents need to be the same so the leading numbers can be added or subtracted.

3. The result has the same number of decimal places as the least precise number.

The exponent is the 10^x that used in scientific notation. .When adding 12.3* 10^5 with 34.56 * 10^4, you need to make the exponent same first. In this case, it would become 12.3* 10^5 + 3.456 * 10^5= 15.756* 10^5

The decimal place could be rounded up to the least precise number. I'm not sure with the significant figures but it seems to use the biggest one.

Explanation:

https://brainly.com/question/7413247

Answer:

54g

Explanation:

Given parameters:

Number of moles of H₂O  = 3 moles

Unknown:

mass of water  = ?

Solution:

To solve this problem, we use the expression below:

         mass  = number of moles x molar mass

Molar mass of H₂O  = 2(1)  + 16  = 18g/mol

Mass of water  = 3 x 18  = 54g

Explanation:

1) their is no formation of new substance

2) the reaction can be reverse i.e if we heat sugar solution it we give us sugar and water.

Answer:

C4H4O

Explanation:

1.24 g x 1mol/(44)g = 0.03mol C;

Mass of C: 0.03mol x 12.g/1mol

= 0.36g of C

mol of H: 0.255g x 1mol /(18) x2= 0.028mol

Mass of H; = 0.028g × 1 of H

Mass of O: 0.519 g – (0.36g +0.028g)= 0.131g;

0.131g/16 =0.008 mol

Divide by the smallest number of moles;

0.028/0.008 mol = 3.5; 0.03/0.008 mol =3.75, 0.008 mol/0.008 mol =1

C4H4O

Answer:

it is calcium and bromine

Explanation:

this is because they are both ionic compounds

Answer:

each year they are adding £31.25 to the bank account as £31.25 =£375 and times by 5 is £1875 but i did not include the $100 at the beginning

Explanation:

Answer and Explanation:

Inspiration for new types of synthetic materials come from natural materials where a derivative is needed to be used in situations where properties of a natural material are adjusted. Inspirations for new types of synthetic materials can also come from current synthetic materials that create toxins, and new ones are created with the same properties but with less harmful downsides.

Answer: conduction

Explanation:

the heat passes out of the stove and into your hand. So is holding an ice cube – the heat is conducted out of your hand, and into the ice cube (that’s why your hand feels cold).

Answer:

Conduction

Explanation:

Conduction occurs when objects touch. The heat from the warmer object is transferred to the cooler object, eventually evening out the temperatures.

Answer:

B) weathering and erosion

Explanation:

The two processes responsible for changing metamorphic and igneous rocks into sedimentary rocks is weathering and erosion.

Weathering is the defined as the physical disintegration and chemical decomposition of rocks to form sediments and soils.

Erosion is the removal of weathered materials from the surface of the earth.

The process of erosion and weathering serves to convert igneous and metamorphic rocks into sediments by which a sedimentary rock is formed.

Answer: The rock cycle

Explanation: Well its kinda obious that it is the rock cycle because the question says it changes countinuously to other rocks so yeah rock cycle is answer to question.

Answer: 84%

Explanation:

Using the table attached, one can find out the Relative humidity.

Look at the intersection between the temperature on the dry bulb and the difference between the temperature on the dry and wet bulb.

Dry bulb temperature = 80°F

Wet bulb temperature = 76°F

Difference = 80 - 76 = 4°F

Relative humidity is therefore:

= 84%