what element is a F-18 Atom

The greatest positive enthalpy change has PCl₅(g) → P(g) + 5Cl(g)

An enthalpy change is difference between the enthalpy after the chemical reaction has completed.

An enthalpy change of phosphorus(V) chloride (PCl₅) molecule is energy needed for breaking up one molecule of phosphorus(V) chloride into one phosphorus and five chlorine atoms.

In a chemical reaction, chemical bonds are forming and breaking and this cause the transformation of one group of chemical substances to another.

Energy is needed to break chemical bonds in molecules (positive enthalpy change), while during formation of molecule, energy is released (negative enthalpy change)

The stronger are the bonds, more energy is needed and enthalpy change is more positive.

PCl₅ has more bonds to break than PCl₃.

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Answer:

In CH4 bond angle is 109.5 but it is slightly less than 109.5 in SF2 both compounds have same hybridization SP3 but bond angle of SF2 is less due to presence of two lone pairs

Explanation:

Answer:

37.5 miles per hour....

Answer:

the wave is reflected. it starts heading towards the other direction

Explanation:

Answer:

Molecule

Explanation:Water is an molecule.

Answer:

Molecule

Explanation:

water is a Molecule

Answer:

Average atomic mass of uranium = 237.97 amu

Explanation:

Given data:

Abundance of U-234 = 0.01%

Abundance of U-235 = 0.71%

Abundance of U-238 = 99.28%

Average atomic mass of uranium = ?

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) + (abundance of 3rd isotope × its atomic mass)  / 100

Average atomic mass  = (234×0.01)+(235×0.71)+(238+99.28) /100

Average atomic mass =  2.34 + 166.85+23628.64 / 100

Average atomic mass = 23797.83 / 100

Average atomic mass = 237.97 amu.

Energy releases to the surroundings = -32.2 kJ

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

mass of coffee(m) = 140 g

∆T = temperature difference :

final temperature - initial temperature = 20-75=-55°C

specific heat coffee= specific heat water = 4.18 J/g° C  

The heat releases :

[tex]\tt Q=140\times 4.18\times -55\\\\Q=-32186~J\approx -32.2~kJ[/tex]

Answer:

Indegestion I believe as there isn't as much bacteria to break down his food.

Explanation:

Tbh, dont complain if you don't like a food, because when you chew it, its gonna turn into some white mush anyways, and when it comes out, its brown.

Dont blame me, blame your tooth.

Answer:

Explanation:

The only difference between the options are the sign. The sign between the two is an arrow to represent the change.

(I know this because we're learning about it in class and it's an arrow not an equal, greater, or less than sign)

Answer:

b i think because i think so

Answer:

im stuck on it too unfortunatley

Explanation:

The density of water is approximately 1.0 g/mL. So, the block will float in water because it is less dense than water.

Density is a scalar quantity. It is calculated as the mass divided by the volume.

The density of water is approximately 1.0 g/mL

The volume of 1.2 x 10^4 in^3

and weighing 350 lb

D = m / v where D is density, m is mass and v is volume

Converting  1.2 x 10⁴ into 10³

1.2 x 10⁴ in ³ (16.39 mL/ 1 in3) = 196,980 mL

Converting   350 lb into grams

350 lb (454 grams/1 lb) = 158,900 grams

D = m / v  = 158,900 grams / 196,980 mL

D = 0.807 g/mL

Thus, due to its lower density than water, the block will float in the water.

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The question is incomplete. Your most probably complete question is given below:

A material will float on the surface of a liquid if the material has a density less than that of the liquid. Given that the density of water is approximately 1.0 g/mL, will a block of material having a volume of 1.2 x 10^4 in^3 and weighing 350 lb float or sink when placed in a reservoir of water?

Answer:

6.408924056 miles/hour.

Explanation:

First we have to convert 247.54 km to miles. The conversion factor will be 1 km = 0.621371 miles. To do this I set up my stoichiometry.

247.54km | 0.621371miles = 153.8141773 miles

                 |  1 km

Now we have 153.8141773 miles per 1 day. The conversion factor will be 1 day = 24 hours.

153.8141773 miles | 1 day       6.408924056 miles/hour.

1 day                      | 24 hours

(if you need to know what I did with the stoichiometry just ask! I'll be happy to help!)

Answer:

79.7 g He

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

1.20 × 10²⁵ atoms He

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of He - 4.00 g/mol

Step 3: Convert

[tex]1.20 \cdot 10^{25} \ atoms \ He(\frac{1 \ mol \ He}{6.022 \cdot 10^{23} \ atoms \ He} )(\frac{4.00 \ g \ He}{1 \ mol \ He} )[/tex] = 79.7077 g He

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

79.7077 g He ≈ 79.7 g He

Answer:

gain electrons

Explanation:

"atoms gain electrons, they acquire a negative charge "

Answer:

To verify the law of Conservation of mass in a chemical reaction.

Write the formulae of the following-

a) Magnesium hydroxide

b) Hydrogen sulphide

c) Calcium oxide

d) Barium chloride

e) Sodium carbonate

f) Ammonium sulphate

g) Aluminium oxide

h) Magnesium bicarbonate

i) Aluminium phosphate

j) Silver nitrate

Answer: 2.07 M

Explanation:

(1.5m) (345ml)

---------------------

250 ML = 2.07M

Answer:

Pure Water  

Explanation:

Battery acid is well and acid

Bleach is a base

Ocean water is impure so it could lean either way

Answer:

valency of an element is a combining power of an element.

for example oxygen has six valance electron but its valency is 2.

hope it helps.

Answer: The formula mass (formula weight) of a molecule is the sum of the atomic weights of the atoms in its empirical formula. The molecular mass (molecular weight) of a molecule is its average mass as calculated by adding together the atomic weights of the atoms in the molecular formula.

Hope this helps.... Stay safe and have a great weekend!!!!! :D

The unknown material : gold

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume  

mass of unknown the material : 15.06 g

volume = 0.78 ml

The density :

[tex]\tt \rho=\dfrac{m}{V}\\\\\rho=\dfrac{15.06}{0.78}=19.31~g/ml[/tex]

materials that match the density: gold

Answer its a

Explanation:

The wavelength of a 1.32 x 10-⁶ eV wave is 0.939m or 9.39 × 10⁸nm.

The wavelength of a wave can be calculated using the following formula:

wavelength = speed ÷ frequency

However, the frequency of the wave needs to be calculated first using the formula as follows:

E = hf

Where;

1 electronvolt = 1.602 × 10-19 joule

Hence, 1.32 × 10-⁶ eV is equivalent to 2.11487 × 10-²⁵J.

2.11487 × 10-²⁵J = 6.626 × 10-³⁴ × f

f = 2.11487 × 10-²⁵ ÷ 6.626 × 10-³⁴

f = 3.2 × 10⁸Hz

Wavelength = 3 × 10⁸ ÷ 3.2 × 10⁸

Wavelength = 0.9375 × 10⁰

Wavelength = 0.94m

Therefore, the wavelength of a 1.32 x 10-⁶ eV wave is 0.939m.

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Answer:

2 second

Explanation:

yes

Answer:

in the movie ' Coco '.........

Two non-metals become more stable by sharing valence electrons and forming covalent compounds.

Covalent compound is defined as a type of compound which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.

Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.

Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.

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Answer:

Runoff is water from precipitation that along with the ground level to water bodies while infiltration is water that seeps through into the soil and could possibly become groundwater.

Explanation:

Normally, where there are more cities and capitals and fewer trees, there would be more runoff and flooding would happen more frequently. In the countryside, there would be more trees and roots that would absorb the water from the soil and thus there would be more infiltration.