What is the step that usually comes last in solving numeric problems

Sodium-22 remain : 1.13 g

The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.  

Usually, radioactive elements have an unstable atomic nucleus.  

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{T/t\frac{1}{2} }}}[/tex]

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

half-life = t 1/2=2.6 years

T=15.6 years

No=72.5 g

[tex]\tt Nt=72.5.\dfrac{1}{2}^{15.6/2.6}\\\\Nt=72.5.\dfrac{1}{2}^6\\\\Nt=1.13~g[/tex]

In model of molecules, gray spheres are carbon atoms, white spheres are hydrogen atoms , red spheres are oxygen atoms and blue spheres are nitrogen atoms. the model represent a molecule of NH₃ is model (A) that contains one blue sphere and 3 white sphere.

Ammonia (NH₃ ) is formed  with three atoms of hydrogen and one atom of nitrogen. In the molecule of NH₃ , three hydrogen atoms each shares their electron with nitrogen and form the covalent bond and molecule is formed NH₃ . in the given model (A) 3 white spheres of hydrogen are covalently bonded with one blue sphere of nitrogen.

Thus, In model of molecules, gray spheres are carbon atoms, white spheres are hydrogen atoms , red spheres are oxygen atoms and blue spheres are nitrogen atoms. the model represent a molecule of NH₃ is model (A) that contains one blue sphere and 3 white sphere.

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Answer:

The mass of water is known to be 1 g/mL or 1 g/cm3. If an object has a density greater than 1 g/cm3, it is denser than water and will sink. If it has a density of less than 1 g/cm3, it will float. For example, a penny is made out of zinc (7.14 g/cm3) and copper (8.96 g/cm3) so it sinks in water.

Explanation:

Answer:

B. Divergent

The rift formed in the Divegent tectonic boundary between the North America and Eurasian Plates and is located now in Iceland (Im sorry im not good at explaining)

Answer:

the globuler cluster

Explanation:

hope this helps maybe next time show anwsers

Answer:

Energy, [tex]E=2.92\times 10^{-19}\ J[/tex]

Explanation:

Given that,

The wavelength of a light is [tex]6.8\times 10^2\ nm[/tex]

We need to find the energy of light. The formula for the energy of light is given by :

[tex]E=\dfrac{hc}{\lambda}\\\\E=\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{6.8\times 10^2\times 10^{-9}}\\\\E=2.92\times 10^{-19}\ J[/tex]

So, the energy of a light is [tex]2.92\times 10^{-19}\ J[/tex].

Answer:

1.00784 u

Explanation:

Answer:

1.00784 u

Explanation:

hydrogen atomm

Answer:

Shape?

Explanation:

that's the only thing that would make sense

Answer:

Shape  

is the answer

Answer:

1-There Must be some displacement in the direction of force.                                                  2-Angle between force and displacement is 0°.                                                                            

Answer:

1.cation

2.anion

Explanation:

the plus is always cation and the negative is anion

Answer:

1. cation

2. anion

Explanation:

A positive ion is always cation and the negative ion is anion

Answer:

B. Hypothese

Explanation:

Answer:

B.Hypothese

Explanation:

i don't know but that's first came in my mind

I clean with a rag wdym

Answer:

I think it is a color but I'm not completely sure

Answer:

Color

Explanation:

Explanation:

hope it helps you please make me brainlest (it's a photo)

Answer:

According to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas? The motion of the gas particles is random and in a straight-line.

Explanation:

Answer:

its 1.86 x 105

Explanation:

i learned it last year

Answer:

1.86 x 10^5

plz, mark brainliest

Answer:

The answer is A. Construction. The production of raw materials for construction in factories is harmful for the environment due to CO2 emissions. The chemicals used in construction and the diesel used by construction vehicles are also harmful to the environment.

Explanation:

In an ecosystem , human activity which constitutes to air pollution is construction.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the ecosystem through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.There are different types of ecosystems.

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Answer:

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.

Explanation:

Answer:

Well, Aluminum Oxide has a very high melting point. Carbon dioxide has a very low boiling point.

Explanation:

They are both talking about different things, melting and boiling. Aluminum Oxide's melting point is much higher then carbon dioxide's melting point. Hope this help, and good luck on your assignment (if one)

Answer:

dressing is for salad and tea is a drink but the are both liquids and brown

Answer:

E.) 1s^22s^22p^23s^4p^4

Explanation:

Answer:

See explanation.

Explanation:

D. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d8;

Explanation: before filling 3d orbitals, 4s needs to be filled. Since s holds 2 electrons, take two from the 3d10.

E. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p3;

Explanation: after the 4s orbital, the 3d orbitals need to be filled. You do not fill the 4d orbitals until the 5s orbital is filled.

Here is a quick review of the order orbitals need to be filled in:

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p;

s holds 2 electrons; p holds 6 electrons; d holds 10 electrons; f holds 14 electrons.

Answer:

Pressure is an important physical quantity—it plays an essential role in topics ranging from thermodynamics to solid and fluid mechanics. As a scalar physical quantity (having magnitude but no direction), pressure is defined as the force per unit area applied perpendicular to the surface to which it is applied. Pressure can be expressed in a number of units depending on the context of use.

Explanation:

Probably not the best answer but hope this helps somewhat. :)

Answer:

yes they are minerals becomes they contain components that have things minerals contians.

Explanation:

It is most accurate to say that body mass index (BMI) provides information about an individual's height-weight ratio.

BMI takes into account natural variations in body shape, giving a healthy weight range for a particular height.

As well as measuring your BMI, healthcare professionals may take other factors into account when assessing if you're a healthy weight individual.

Muscle is much denser than fat, so very muscular people, such as heavyweight boxers, weight trainers and athletes, may be a healthy weight even though their BMI is classed as obese.

Your ethnic group can also affect your risk of some health conditions. For example, adults of South Asian origin may have a higher risk of some health problems, such as diabetes, with a BMI of 23, which is usually considered healthy.

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Answer:

a hypothesis

Explanation:

A hypothesis is a statement that is supposed or assumed before conducting any experiment. It is the assumption that is made on the basis of certain knowledge and controlled evidence in the initial time of the experiment. The initial assumption helps in taking the experiment or the investigation further. The truth is not ascertained in the initial phase rather the completion of the investigation is necessary to make a hypothesis turn into a theory.  

In the given situation, the statement given is a hypothesis because the use of the warm water for the growth of the plants is the assumption made with respect to the metabolism effect on the humans.

Answer:

Explanation:

set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules[1

Answer:

4477381.7 calories/pound

Explanation:

It is given that,

When a candle burns it produced 41,300 Joules per 1 gram.

We need to convert it into calories per pound.

We know that,

1 cal = 4.184 J

⇒ 1 J = (1/4.184) cal

1 pound = 453.592 grams

⇒1 g = (1/453.592) pounds

Now,

[tex]41300\ \text{Joules per gram}=\dfrac{41300\ \text{Joules}}{\text{gram}}\\\\=41300\times \dfrac{\dfrac{1}{4.184}\ \text{calories}}{\dfrac{1}{453.592}\ \text{gram}}\\\\=4477381.7\ \text{calories/pound}[/tex]

Hence, 41,300 Joules/gram = 4477381.7 calories/pound.

Answer:

One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant.

Explanation:

hope this helped!

Answer:

H⁺(aq) + OH⁻(aq) = H₂O(l)

Explanation:

To find the net ionic equation start by finding the balanced equation.

2HClO₄(aq) + Ba(OH)₂(aq) ⇒ 2H₂O(l) + Ba(ClO₄)₂(aq)

Then put it into the ionic equation.

2H⁺(aq) + 2ClO₄(aq) + Ba²⁺(aq) + 2OH⁻(aq) ⇒ 2H₂O(l) + Ba²⁺(aq) + 2ClO₄(aq)

Remove all the ions that do not change.

2H⁺(aq) + 2OH⁻(aq) ⇒ 2H₂O(l)

And reduce to the lowest common coefficient.

H⁺(aq) + OH⁻(aq) = H₂O(l)