The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later

Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question

volume of liquid = 15 mL

density = 2.5 g/mL

We have

mass = 15 × 2.5

We have the final answer as

Hope this helps you

The correct Lewis Dot Structure for Nitrogen is structure C. Therefore, option C is correct.

The valence shell electrons in a molecule are depicted in an extremely simplified manner by a Lewis Structure. It is used to demonstrate how the electrons in a molecule are positioned around particular atoms.

Gilbert N. Lewis, who first described it in his 1916 article The Atom and the Molecule, gave the Lewis structure its name. Lewis structures add lines between atoms to represent shared pairs in a chemical bond, extending the idea of the electron dot diagram.

In Nitrogen molecule, every nitrogen atom has five valence electrons and there is a triple bond between the two nitrogen atoms. Thus, the correct lewis dot structure is; :N⋮⋮N: .

Thus, option C is correct.

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Answer:

1*6

Explanation:

The question is incomplete, the complete question is;

One tank of goldfish is feed the normal amount which is once a day, a second tank is fed twice a day, and a third tank is fed four times a day during a 6 week study. The fishes' body fat is recorded daily.

Independent Variable-

Dependent Variable-

Constants

Control Group-

Answer:

A) The amount of food the gold fish receives

B) Body fat of the gold fish

C) -Type of fish used in the study (gold fish)

Time period within which the fishes were fed (Six week period)

Shape and size of tank

D) group of gold fish fed the normal amount

Explanation:

The purpose of the study is to determined the impact of amount of feed on the body fat of gold fish. Hence, the amount of feed is the independent variable while the body fat of the feed is the dependent variable.

The control group receives the normal amount of feed (once a day). The fishes are all gold fish, fed within a six week period. All the tanks were of the same shape and size. These are the constants in the study.

Answer: Salt is primarily composed of sodium chloride.

Explanation:

Answer:

The volume of container is 39.14 L.

Explanation:

Given data:

Number of moles of neon = 4.0 mol

Pressure of gas = 2.5 atm

Temperature of gas = 25°C

Volume of container = ?

Solution:

we will use general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

25+273 = 298 K

Now we will put the values in formula.

2.5 atm × V = 4.0 mol × 0.0821 atm.L/ mol.K ×  298 K

V = 97.86 atm.L /2.5 atm

V = 39.14 L

The volume of container is 39.14 L.

Answer: la masa porque a lo largo del tiempo se fueron creando planetas por todo el universo

Explanation:

Answer:

Protons and Neutrons

Explanation:

Answer:

a) [tex]BaF_{2}[/tex]

b) [tex]SnCl_{4}[/tex]

c) [tex]Cr_{2}O_{3}[/tex]

d) [tex]FeO[/tex]

e) [tex]Li_{3} P[/tex]

Explanation:

The charges of the ions have to be 0, so they balance.

a) [tex]Ba^{2+}[/tex] has the charge of +2 and [tex]F^{-}[/tex] has the charge of -1. So its [tex]0=(+2)+(-1)*2[/tex]. That means you need one [tex]Ba^{2+}[/tex] and two [tex]F^{-}[/tex] to balance the equation. -> [tex]BaF_{2}[/tex]

b) [tex]Sn^{4+}[/tex] has the charge of +4 and [tex]Cl^{-}[/tex] has the charge of -1. So its [tex]0=(+4)+(-1)*4[/tex]. That means you need one [tex]Sn^{4+}[/tex] and four [tex]Cl^{-}[/tex] to balance the equation. -> [tex]SnCl_{4}[/tex]

c) [tex]Cr^{3+}[/tex] has the charge of +3 and [tex]O^{2-}[/tex] has the charge of -2. So its [tex]0=(+3)*2+(-2)*3[/tex]. That means you need two [tex]Cr^{3+}[/tex] and three [tex]O^{2-}[/tex] to balance the equation. -> [tex]Cr_{2}O_{3}[/tex]

d) [tex]Fe^{2+}[/tex] has the charge of +2 and [tex]O^{2-}[/tex]has the charge of -2. So its [tex]0=(+2)+(-2)[/tex]. That means you need one [tex]Fe^{2+}[/tex] and one [tex]O^{2-}[/tex] to balance the equation. -> [tex]FeO[/tex]

e) [tex]Li^{+}[/tex] has the charge of +1 and [tex]P^{3-}[/tex]has the charge of -3. So its [tex]0=(+1)*3+(-3)[/tex]. That means you need three [tex]Li^{+}[/tex] and one [tex]P^{3-}[/tex] to balance the equation. -> [tex]Li_{3} P[/tex]

Answer:

i think its k.

Explanation:

position k im sure

Answer:

Calcium cyanamide

Explanation:

I think it has to be calcium cyanide, because of the cyanamide ion (CN).

Answer:

The lattice energy decreases down the group and increases across the period, therefore, the lattice energy of LiF > lattice energy of LiI, and the lattice energy of NaCl < the lattice energy of AlCl₃

Explanation:

The given parameters are;

Compound [tex]{}[/tex]                                    Lattice Energy (kJ/mol)

LiF  [tex]{}[/tex]                                                     1030

NaCl  [tex]{}[/tex]                                                  788

MgCl₂  [tex]{}[/tex]                                                2326

LiI  [tex]{}[/tex]                                                       730

AlCl₃   [tex]{}[/tex]                                                  5376

Lattice is the energy that must be added in order to split one mole of a ionic solid compound into gaseous ions

Given that the force of attraction between charges is inversely proportional to the square of the distance separating the charges, we have that as the atomic radius increases progressively down the group, the lattice energy decreases, therefore, LiF which has a shorter inter nuclear distance than LiI due to fluorine, F, being higher up on the periodic table than iodine, I, has a greater lattice energy than LiI

Similarly, given that the atomic radius decreases across the period, and that sodium, Na, comes before aluminum, Al, as we move across period 3, of the periodic table, the inter nuclear distance between atoms of in NaCl is larger than the internuclear distances between the atoms of AlCl₃, as well as the presence of more chlorine atoms in AlCl₃ than in NaCl, the lattice energy of NaCl is smaller than the lattice energy of AlCl₃.

Answer:No

Explanation:

Well yes but no, There cant be high tempreture that is 100 degrees and a low tempreture that is 20 degress, there has to be a mid inbetween both, they cant be next to eachother.

Answer:

V = l * w * h

V = 150.00 mm x 1cm/10 mm x 10.00 cm x 0.95 m x 100 cm/1 m = 1.4 x 104 cm3 D = M/V

M = D * V = 19.3 g/cm^3 * 1.4 * 104 cm^3 = 2.7 x 10^5 g = 270000 grams

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume}\\[/tex]

From the question

mass = 8.32 g

volume = 4.3 mL

So we have

[tex]density = \frac{8.32}{4.3} \\ = 1.934883720...[/tex]

We have the final answer as

Hope this helps you

Answer:

D. The government determines what is right & wrong for everyone

Explanation:

Answer:

It is true , that the tropical zone experiences the trade winds .

Explanation:

TRADE WINDS -: The trade winds or easterlies are the dominant east-to - west permanent winds that flow in the equatorial area of the Planet (between latitudes 30 ° N and 30 ° S). In the Northern Hemisphere, the trade winds blow primarily from the northeast and from the southeast in the Southern Hemisphere, strengthening throughout the winter and when the Arctic oscillation is in its warm phase. Trade winds have been used by sailing ship captains for centuries to cross the world's oceans and have enabled colonial expansion into the Americas and the construction of trade routes across the Atlantic and Pacific oceans. They act as the steering flow for tropical storms in meteorology. developing over the Atlantic , Pacific, and Southern Indian Oceans and landing in North America, Southeast Asia, Madagascar, and East Africa. Under trade wind regimes, shallow cumulus clouds are seen and are capped from being larger by a trade wind inversion induced by downward air aloft from within the subtropical ridge.

When trade winds blow through tropical areas , due to more direct sunlight , air masses heat up across lower latitudes. Those that develop over (continental) land are drier and hotter than those that develop over (maritime) oceans and travel northward to the subtropical ridge 's western periphery. Masses of maritime tropical air are often referred to as masses of commercial air. There are extensive areas of trade winds in all tropical oceans except the northern Indian Ocean.

Hence , the statement is true.

The challenges do scientists face in studying the sun is that due to high amount of heat, it is impossible to see sun.

Sun is a ball of hydrogen and helium gases which may produce large amount of heat as a result of nuclear fusion reaction.

High amount of heat is produced in the sun so it is not possible to see the sun from the normal eyes. Scientist uses telescope with mant filters to see a clear picture of the sun. Scientists are also not able to go near to the sun as produced heat is that much of power as they burn any object.

Hence above challenges are scientist face.

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carbon monoxide: CO

water:H2O

salt:NaCl

copper: Cu

Answer:

2 C7H6O2 + 15 O2 --> 14 CO2 + 6 H2O

Explanation:

Answer:

Alkaline Earth Metals

Explanation:

:)

Answer:

Transition zone of the sun

Explanation:

Transition Region - The transition region is a very narrow (60 miles / 100 km) layer between the chromosphere and the corona where the temperature rises abruptly from about 8000 to about 500,000 K (14,000 to 900,000 degrees F, 7700 to 500,000 degrees C).

Answer:

8368 Joules

Explanation:

Answer:

Option D is correct.

H₂O + CO₂      →    H₂CO₃

Explanation:

First of all we will get to know what law of conservation of mass states.

According to this law, mass can neither be created nor destroyed in a chemical equation.

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

Example:

6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂

there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.

Now we will apply this law to given chemical equations:

A) H₂ + O₂   →    H₂O

There are two hydrogen and two oxygen atoms present on left side while on right side only one oxygen and two hydrogen atoms are present so mass in not conserved. This equation not follow the law of conservation of mass.

B) Mg + HCl   →   H₂ + MgCl₂

In this equation one Mg, one H and one Cl atoms are present on left side while on right side two hydrogen, one Mg and two chlorine atoms are present. This equation also not follow the law of conservation of mass.

C) KClO₃      →     KCl + O₂

There are one K, one Cl and three O atoms are present on left side of chemical equation while on right side one K one Cl and two oxygen atoms are present. This equation also not following the law of conservation of mass.

D)  H₂O + CO₂      →    H₂CO₃

There are two hydrogen, one carbon and three oxygen atoms are present on both side of equation thus, mass remain conserved. Thus is correct option.

The chemical reaction that follows the conservation of mass has been the formation of hydrogen carbonate. Thus, option D is correct.

The conservation of mass states that the mass of the reactant and products has been equal. The mass can be calculated in terms of the number of atoms.

(A) [tex]\rm H_2\;+\;O_2\;\rightarrow\;H_2O[/tex]

The number of atoms of Hydrogen:

Reactant = 2

Product = 2

The number of atoms of Oxygen:

Reactant = 2

Product = 1

The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.

(B) [tex]\rm Mg\;+\;HCl\;\rightarrow\;H_2\;+\;MgCl_2[/tex]

The number of atoms of Mg:

Reactant = 1

Product = 1

The number of atoms of H:

Reactant = 1

Product = 2

The number of atoms of Cl:

Reactant = 1

Product = 2

The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.

(C) [tex]\rm KClO_3\;\rightarrow\;KCl\;+\;O_2[/tex]

The number of atoms of K:

Reactant = 1

Product = 1

The number of atoms of Cl:

Reactant = 1

Product = 1

The number of atoms of O:

Reactant = 3

Product = 2

The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.

(D) [tex]\rm H_2O\;+\;CO_2\;\rightarrow\;H_2CO_3[/tex]

The number of atoms of H:

Reactant = 2

Product = 2

The number of atoms of O:

Reactant = 3

Product = 3

The number of atoms of C:

Reactant = 1

Product = 1

The number of atoms of products and reactant is equal, Thus, the reaction follows the conservation of mass.

The chemical reaction that follows the conservation of mass has been the formation of hydrogen carbonate. Thus, option D is correct.

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Answer:

A

Explanation:

The moon is connected to the ocoen

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