Which statement is not true about the periodic table?
A. Elements in the same family have the same number of protons.
B. An element of the table is represented by a box with a symbol in it.
C. Elements in the same period of the periodic table have the same
number of electron shells.
D. It is organized by atomic number.

Answer:

B.Thermal insulation minimizes energy loses to the atmosphere.

Explanation:

It is important because it helps to stop hit from transferring from the calorimeter to the environment. This would help to have an accurate measurement of the heat that was used in the chemical process. The greatest cause of error that happens in calorimetry is when heat is lost to the environment. To reduce this, you insulate the calorimeter and add a cover.

Answer: The heat energy produced is 53831.25KJ

Explanation:

METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:

Molecular mass of methane =16 gm/mol.

So moles of 1 kg methane =

Given mass of methane ÷ molecular weight of methane

But the given mass = 1kg = 1000g

Therefore,

moles of 1000g methane = 1000÷16

= 62.5 moles

Hence, energy evolved = (moles of methane) × (heat of combustion)

Therefore,

heat energy produced= 62.5 × (-861.3kj)

= -53831.25kj

​

The heat energy produced by the combustion of one kilogram of methane is –53831.25 KJ

We'll begin by calculating the number of mole in 1 Kg of CH₄

Mass of CH₄ = 1 kg = 1000 g

Molar mass of CH₄ = 12 + (4×1) = 16 g/mol

Mole = mass /molar mass

Mole of CH₄ = 1000 / 16

CH₄ + 2O₂ —> CO₂ + 2H₂O ΔH = –861.3 KJ

From the balanced equation above,

1 mole of CH₄ reacted to produce –861.3 KJ.

Therefore,

62.5 moles of CH₄ will react to produce = 62.5 × –861.3 = –53831.25 KJ

Thus, –53831.25 KJ of heat energy is produced.

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Answer:

1807.24L

Explanation:

Using combined gas law equation:

P1V1/T1 = P2V2/T2

Where;

P1 = pressure on Earth

P2 = Pressure on Mars

V1 = volume on Earth

V2 = volume on Mars

T1 = temperature on Earth

T2 = temperature on Mars

According to the information provided of the balloon in this question;

P1 = 1 atm

P2 = 4.55 torr = 4.55/760 = 0.00599atm

V1 = 14.5L

V2 = ?

T1 = 19°C = 19 + 273 = 292K

T2 = -55°C = -55 + 273 = 218K

Using P1V1/T1 = P2V2/T2

1 × 14.5/292 = 0.00599 × V2/218

14.5/292 = 0.00599V2/218

Cross multiply

14.5 × 218 = 292 × 0.00599V2

3161 = 1.74908V2

V2 = 3161 ÷ 1.74908

V2 = 1807.24L

Explanation:

hope it helps thanks ❤

brainliest please

Answer:

Explanation:

human obtains energy by eating food. as food is digested n broken down in our digestive system, energy is released to our body.

Answer:

any 5 ways to prevent earth are:

1.using ( 3R) principles Reduce, reuse, and recycle.

2.Educate yourself

3.Conserve water resources and other natural resources

4.Use long-lasting light bulbs.

5.stop deforestation and start afforestaion

Answer:

3.01×10²⁶ molecules

Explanation:

From the question given above, the following data were obtained:

Mass of H₂ = 1 Kg

Number of molecules =?

From Avogadro's hypothesis,

1 mole of H₂ = 6.02×10²³ molecules

But 1 mole of H₂ = 2 × 1 = 2 g

Now, we shall determine the number of molecules present in 1 Kg (i.e 1000 g) of H₂ as follow:

From Avogadro's hypothesis,

2 g of H₂ = 6.02×10²³ molecules

Therefore,

1000 g of H₂ = 1000 × 6.02×10²³ / 2

1000 g of H₂ = 3.01×10²⁶ molecules

Thus, the number of molecules present in 1 Kg (i.e 1000 g) of H₂ is 3.01×10²⁶ molecules

Answer:

B

pls correct me if im wrong

Answer:

3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?

Explanation:

Put these atoms in order from most negative overall charge to least negative

overall charge.

11 Atom X: 104 protons, 102 electrons

11 Atom B: 24 protons, 18 electrons

1 Atom Q: 15 protons, 16 electrons

11. Atom P: 7 protons, 10 electrons

Answer:

i am so sorry. i do not have a answer but i am trying to find questioms i can answer

Answer:

aefhfcjd

Explanation:

Explanation:

For both men and women, the basics of a balanced diet are the same. Men have higher caloric requirements than women since they have a bigger body (both in height and weight) and more muscular mass.

So, Men needs more energy.

50 year old woman require less energy than 50 year old man.​

Answer:

Organ System

Explanation:

These organs are helping each other process food and therefore be an Organ System

Both have Giant Covalent Structures, resulting in very high melting temperatures. However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layers.

Answer:

Please find the definition and further explanation below

Explanation:

Based on the ability for the solvent (liquid substance) to dissolve a solute (solid substance), a solution can either be unsaturated, saturated or supersaturated. A SATURATED SOLUTION is that which contains the maximum amount of solute a solvent can possibly dissolve.

In other words, a saturated solution can no longer dissolve anymore solute, and hence, any further solute added forms crystals or makes the solution supersaturated.

Answer:

When ΔS > 0 and ΔH < 0, the process is always spontaneous as written. When ΔS < 0 and ΔH > 0, the process is never spontaneous, but the reverse process is always spontaneous. When ΔS > 0 and ΔH > 0, the process will be spontaneous at

Explanation:

What are the best conditions to lead towards a spontaneous reaction? high negative enthalpy, high temp, high positive entropy. Your enthalpy is high and negative but your entropy is also negative.

Answer:

the moving of something form it's places or position

Viruses are known as obligatory parasites as they only become active and multiply when inside a host. Viruses are inactive when they are outside.

Answer:

Unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Explanation:

Living things made up of a cell are called unicellular beings. They are very small and simple. In other words, unicellular organisms are those that are formed only by a single cell in which all the vital functions necessary for life are produced. For this reason, they are mostly microscopic organisms. Examples of unicellular organisms are viruses or bacteria.

Multicellular organisms are made up of a large number of cells. They present, therefore, a greater complexity than unicellular organisms in terms of the functions they develop. All current multicellular organisms come from a single cell, that is, they begin their life being unicellular. That is, they are formed from a zygote. Some examples of multicellular organisms are mammals, fungi, and mosses.

So, unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Answer:

-2,802.960 kJ

Explanation:

The dimensional equation of the given quantities is presented as follows;

(6 mol) × (-393.5 kJ/mol) + (6 mol) × (-285.83 kJ/mol) - (1 mol) × (-1,273.02 kJ/mol) = ? kJ

The equation, can be written as follows;

[tex]\left (6 \times (-393.5) \, mol \times \dfrac{kJ}{mol} \right ) + \left(6 \times (-285.83) \, mol \times \dfrac{kJ}{mol} \right) - \left (1 \times (-1,273.02) \, mol \times \dfrac{kJ}{mol} \right) = ?[/tex]We note that [tex]mol \times \dfrac{kJ}{mol} \right) = kJ[/tex], therefore, the above equation becomes;

[tex]\left (6 \times (-393.5) \ kJ\right ) + \left(6 \times (-285.83) \ kJ \right) - \left (1 \, \times (-1,273.02) \ kJ \right) = -2,802.960 kJ[/tex]

Answer:

C. ((6 mol)(-393.5 kJ/mol) + (6 mol)(-285.83 kJ/mol)) - (1 mol)(-1,273.02 kJ/mol)

Explanation:

Got it right on edge.
: the one after is -2803.

Explanation:

Balanced chemical equation for above reaction :

[tex] \mathrm{Cu +2 \: AgNO_3 \longrightarrow Cu(NO_3)_2 + 2 \: Ag}[/tex]

This is a displacement reaction, where copper (Cu) being morereactive than Silver (Ag) displaces Silver from its compound " Silver Nitrate " to form " Copper Nitrate " and silver .

[tex]\mathrm{✌TeeNForeveR✌}[/tex]

(1) Seven electrons

1s² 2s²2p³

There are two electrons in the 2s subshell and three in the 2p subshell. The remaining two electrons are in the inner 1s subshell.

(2) 22 electrons

1s² 2s²2p⁶ 3s²3p⁶ 4s²3d²

There are two electrons in the 4s subshell and two in the 2p subshell. The remaining 18 electrons are in the inner subshells.

(3) 17 electrons

1s² 2s²2p⁶ 3s²3p⁵

There are two electrons in the 3s subshell and five in the 2p subshell. The remaining 10 electrons are in the inner subshells.

(4) n = 4, l = 2

(5) N=2 I=0 MI=0

(6) There can be two electrons in one orbital maximum. The s sublevel has just one orbital, so can contain 2 electrons max. The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max.

(7) n = 4 can hold up to 16 electrons

There are 4 sublevels; 42, 4p, 4d and 4f

4s (1 orbital), 4p (3 orbitals)

4d (5 orbitals), 4f (7 orbitals)

Maximum number of electrons in energy level: 16

s = 1 orbital

p = 3 orbitals

d = 5 orbitals

f = 7 orbitals

Add these up;

1 + 3 + 5 + 7 = 16

(8) 14 electrons If l = 3, the electrons are in an f subshell. The number of orbitals with a quantum number l is 2l + 1, so there are 2×3 + 1 = 7 f orbitals. Each orbital can hold two electrons, so the f subshell can hold 14 electrons.

sorry i didn't do the last two.. also sorry if some or none of these are correct, i tried my best

Answer:

1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride? atoms of boron.

2. How many MOLES of fluorine are present in  of boron trifluoride? moles of fluorine.​

Explanation:

The molecular formula of boron trifluoride is [tex]BF_3[/tex].

So, one mole of boron trifluoride has one mole of boron atoms.

1. The number of boron atoms in 2.20 moles of boron trifluoride is 2.20 moles.

The number of atoms in 2.20 moles of boron is:

One mole of boron has ---- [tex]6.023x10^2^3[/tex] atoms.

Then, 2.20 moles of boron has

-[tex]=2.20 mol. x 6.023 x 10^2^3 atoms /1 mol\\=13.25x10^2^3 atoms[/tex]

2. Calculate the number of moles of BF3 in 5.35*1022 molecules.

[tex](5.35x10^2^2 molecules/6.023x10^2^3)x 1mol\\=0.0888mol[/tex]

One mole of boron trifluoride has three moles of fluorine atoms.

Hence, 0.0888moles of BF3 has 3x0.0888mol of fluorine atoms.

=0.266mol of fluorine atoms.

Answer:

One mole of copper atoms has Avogadro number of copper atoms i.e. 6.022×10

23

 atoms.

Given the mass of Copper is 6.4g

Number of Copper atoms in 6.4g =

molar mass

given mass

​

×Avogadro number

                                                       =

63.55

6.4

​

×6.022×10

23

 copper atoms

                                                       =6.064×10

22

 copper atoms

Explanation:

Answer:

v = 3,000,000,000 m/s

Explanation:

v = f *L

v = 3,000,000 * 1000

v = 3,000,000,000 m/s

Answer:

Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium while environmental chemistry is the study of chemical processes that occur in water, air, terrestrial and living environments, and the effects of human activity on them. 

Physical chemistry is the area of chemistry that deals with how materials interact and change. The scientific study of chemical and biological phenomena that take place in the environment is known as environmental chemistry.

Physical chemistry attempts to quantify, correlate, and explain the quantitative features of reactions by focusing, in contrast to other branches, on the physics principles that underlie all chemical interactions (such as the gas laws).

While environmental chemistry is the study of chemical species' sources, reactions, movement, impacts, and fates in the air, soil, and water environments, as well as the impact of human activity and biological activity on these, can be summed up as the field of chemical ecology.

To learn more about environmental chemistry visit;

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https://brainly.com/question/22517940

Answer: Yes! you're all good. Alkali metals in group 1 are the most metallic :)

Using the idea of the  molar volume of butane gas, we have 2.23 moles of water vapor.

The term reaction equation shows the conversion of reactants to products. First of all, we must get down the reaction equation as follows;

C4H10(g) + 13/2O2(g) ----> 4CO2 (g) + 5H2O(g)

From the balanced reaction equation;

1 mole of  butane gas yields 5 moles of water vapor. Since 1 mole of butane gas occupies 22.4 L. Hence;

22.4 L of butane yields 5 moles of water vapor

10 L of butane gas yields 10 L * 5 moles/22.4 L = 2.23 moles

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Answer:

Explanation:

Lead Monoxide: PbO

Nitric Acid: HNO3

PbO + 2 HNO3 ---> Pb(NO3)2 + H2O

Answer:

Explanation:

mono mean single so lead monoxide is PbO

nitric acid is HNO3

both Pb n O are double-charged while H n NO3 are single

so balanced eqn is:

PbO + 2HNO3 -> Pb(NO3)2 + H2O