Nitrogen-13 emits beta radiation and decays to carbon-13 with a half life of 10
minutes. Assume a starting mass of 2.00 g of nitrogen-13.
(Use to answer the questions below.)
How long is three half-lives in the example above? *

Answer:

i think it's B sorry if i'm wrong

Answer:

[tex]0.75 \times 1000 = [/tex]

Explanation:

Use ur calculator

Answer:

750m

Explanation:

1 km is equal to 1000m. Therefore all you have to do is multiply 0.75 by 1000 and you will get 750. Hope this helps! :)

Answer:

https://www.webqc.org/balance.php

Explanation:

this is the website i used to balance all my chem equations

i promise its not a scam its a legit website lol it works rly well

Answer:

7 is the only basic number on a pH scale

Answer:

the electrons in the innermost shell of an atom are called core electrons while the electrons in the outermost shell are called Valence electrons the arrangement of electrons in the shells of an atom is known as electron configuration.

Explanation:

Alfred wegener collected pieces of evidence to support his theory having to do with geological "fit" and fossil evidence. This means that these extensive oceans between these land masses act as a type of barrier for fossil transfer.

Answer:

The heat flow into Earth's atmosphere varies as the Sun rises and sets, gradually increasing during the day and falling to zero at night.

Explanation:

Heat radiates from the ground into the lower atmosphere. In conduction, heat moves from areas of more heat to areas of less heat by direct contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their energy.

Answer:

Explanation:

1. Please provide the enthalpy info - I will work on it with the info

2.

i) Reaction a should be modified to match the number of S in equation:

 2S + 2O2 -> 2SO2     deltaH = -370kJ

ii) Reaction b should be written reversely to match the reactants of SO2:

 2SO2 + O2 -> 2SO3     deltaH = 256kJ

iii) Adding the equations together:

 2S + 3O2 -> 2SO3

iv) Enthalpy of the combined reaction = -370+256 = -114kJ

 It is negative so the reaction is exothermic.

Answer:

Explanation:

1 c. enthalpy change = enthalphies of formation of all products - enthalphies of formation of all reactants =  -526.3 kcal/mol

1 d. C3H8(g) + 5 O2 (g) → 3 CO2 (g)  + 4 H2O (l)    ΔH = -526.3 kcal/mol

here's your answer..

Answer:

Debido al descubrimiento de protones, neutrones y electrones.

Explicación:

La teoría de Demócrito fue reemplazada por la teoría de Dalton y luego la teoría de Dalton fue reemplazada por la de Rutherford debido al descubrimiento de protones, neutrones y electrones que están presentes dentro del átomo. Demócrito afirma que el átomo es una partícula indivisible de materia, pero el descubrimiento del protón, el neutrón y el electrón cambió este concepto de átomo, por lo que debido al mayor descubrimiento y estudio del átomo y sus partículas subatómicas, las teorías cambiaron con el paso del tiempo.

Answer:

0.0015 M

Explanation:

we know, M = n/V = 2.5/1000 = 0.0015 M

The question is incomplete, the complete question is;

Some carbonated beverages are made by forcing carbon dioxide gas into a beverage solution. When a bottle

of one kind of carbonated beverage is first opened, the beverage has a pH value of 3.

After the beverage bottle is left open for several hours, the hydronium ion concentration in the beverage

solution decreases to 1/1000 of the original concentration. Determine the new pH of the beverage solution.

Answer:

6

Explanation:

Recall that

pH= -log[H3O^+]

Hence, [H^+] when the drink was first opened;

3 = -log[H^3O+]

[H^+] = Antilog(-3)

[H30^+] = 1 * 10^-3

Since [H3O^+] decreases to 1/1000 times its original value;

New [H3O^+] =  1 * 10^-3 * 1/1000 = 1 * 10^-6

Hence,

New pH = -log[1 * 10^-6]

New pH = 6

Answer:

I believe forming an environmental personality is more important than forming a hereditary personality. Why I said this is because of the people around out can change your personality, and sometimes if you're with the wrong people, it can go wrong, with your personality too. You could have been a nice person at some time, you bur you hung out with the wrong people and now you're just very inconsiderate. Another reason on why I believe forming an environmental personality is more important because of the fact that maybe you could've been born with a parent who has a bad personality. You could try your best to be nicer by the choice of people you choose to be friends with.

Explanation:

i hope this helped, im only in 7th

Explanation:

The species with a positive charge over it, which means lack of electrons are called cations. Whereas the species with negative over it, meaning it has an excess of electrons with it are called anions.

From the list given the cations are

H+, Ba2+, Hg2+, Li+, Ca2+ and Fe2+

Whereas anions from the list are

O-2, Br-5, F-, S-2.

A Combination of cation and anions make an ionic compound in which cation is written first and then anion.

Answer:

Products

Explanation:

In an endothermic reaction, energy is taken in. This means that the absorption of energy favours the forward reaction.

Hence for a process; A + B----> C, if energy must be added for the equilibrium to shift towards the right and more of C is produced, then the reaction is endothermic.

Answer:

The pressure at 210 K will be 2.53 atm.

Explanation:

Gay-Lussac's law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions with the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.

This law mathematically indicates that the quotient between pressure and temperature is constant:

[tex]\frac{P}{T} =k[/tex]

You want to study two different states, an initial state and a final state. You have a gas that is at a pressure P1 and at a temperature T1 at the beginning of the experiment. By varying the temperature to a new value T2, then the pressure will change to P2, and the following will be fulfilled:

[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{6.5 atm}{540 K} =\frac{P2}{210 K}[/tex]

Solving:

[tex]P2=210 K*\frac{6.5 atm}{540 K}[/tex]

P2=2.53 atm

The pressure at 210 K will be 2.53 atm.

Answer:

Theoretical 32.04 g

The precent yeild 87. 39 %

Explanation:

Mole of H2 = m/mw = 4/2 = 2 mol

From the equation

1 mol H2 --> 1/2 mol CH3OH

2 mol H2 -->??

So we have 1 mol Ch3oh

Mass of Ch3oh = mole *Mw = 1* 32.04

= 32.04g >>> the theoretically

For percent yeild = actual / theoretical * 100%

( 28.0/32.04) *100% =

87.93%

Answer:

Double bond

Explanation:

Carbon is a tetravalent atom. This implies that the carbon atom always forms four covalent bonds.

These four covalent  bonds may be single, double or triple bonds. Compounds that contain double and triple bonds are said to be "unsaturated".

If the last carbon atom of an unsaturated fatty acid is bonded to two hydrogen atoms and one carbon atom, it means that the bond between the last carbon and the other carbon atom must be a double bond because carbon must be tetravalent and we have already been told that the fatty acid is unsaturated.

The last carbon atom of the unsaturated fatty acid must form two covalent bonds to the other carbon atom in order to respect the tetravalency of carbon.

Answer:

Double bond

Explanation:

its in the book

Answer:

Yes

Explanation:

Due to pollution, greenhouse gasses, etc

Humans are increasingly influencing the climate and the earth's temperature by burning fossil fuels, cutting down forests and farming livestock. This adds enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming.

Answer:

164.3g of NaCl

Explanation:

Based on the chemical equation:

CaCl2 + 2NaOH → 2NaCl + Ca(OH)2

where 1 mole of CaCl2 reacts with 2 moles of NaOH

To solve this question we must convert the mass of CaCl2 to moles. Using the chemical equation we can find the moles of NaCl and its mass:

Moles CaCl2 -Molar mass: 110.98g/mol-

156.0g CaCl₂ * (1mol / 110.98g) = 1.4057 moles CaCl2

Moles NaCl:

1.4057 moles CaCl2 * (2mol NaCl / 1mol CaCl2) = 2.811 moles NaCl

Mass NaCl -Molar mass: 58.44g/mol-

2.811 moles NaCl * (58.44g / mol) = 164.3g of NaCl

Answer:

There are 0.301 moles of N2 gas in 6.75 liters of N2 gas.

Explanation:

Given,

Volume of N2 gas = 6.75 L

We know,

At STP,

Number of moles = [tex]\frac{Volume}{22.4 L}[/tex]   [Here 22.4 liter is the molar volume of any gas at STP]

                              = [tex]\frac{6.75L}{22.4L}[/tex]

                              = [tex]0.301[/tex]

∴There are 0.301 moles of N2 gas in 6.75 liters of N2 gas.

Answer:

Death Valley in California U.S. is the hottest place in the world

Answer:

110.984  ?

i apologize if i'm wrong, you can report it if im wrong

have a good day/ night

Explanation:

Answer:

the ion-dipole forces between the ions and the water molecules

Explanation:

Water is a polar molecule having a high dipole moment. This high polarity makes it a popular choice of polar solvent.

CuSO4 is an ionic compound composed of Cu^2+ and SO4^2-. When dissolved in water, the positive dipole in water interacts with the negative ion while the negative dipole in water interacts with the positive ion thereby causing the compound(CuSO4 ) to dissolve in water due to the ion-dipole forces between the ions and the water molecules.

Answer:

I guess option d

hope I am correct

Answer:

temperature, concentration, pressure

Answer:

Atomic mass is the weighted average mass of an atom of an element based on the relative natural abundance of that element's isotopes. The mass number is a count of the total number of protons and neutrons in an atom's nucleus.

Answer:

Atomic mass is the weighted average mass of atom of an element based on the relative abundance of the element's isotopes. The mass number is a count of total number of protons and neutrons in an atom's nucles