How much of a 100.0 gram sample of Gold-98 remains after 8.1 days if
its half-life= 2.7 days?

50.0 g

12.5 g

6.25 g

25.0 g

Answer:

Assertion (A) is true

but reason (R) is false.

Explanation:

If we look at the assertion closely, it is true that a sublime substance changes from solid to gas without  passing through a liquid state. Naphthalene, camphor, iodine and ammonium  chloride are some common  examples of the substances  which undergo sublimation.

However, not all solids first pass through a liquid state before converting to gas. Sublime solids such as those listed above passes directly from solid to gas without passing through a liquid state.

Hence the assertion is true but reason is false.

Answer: here i am choosing two answer because i am not sure . a gas forms and a solid forms

Explanation: a solid forms thus is to say a precipitate is formed

a gas forms thus to say effervescence , fizzing and bubbling whiles a gas is being produced.

Answer:

3.60

Explanation:

To calculate the pH of any solution, use the formula;

pH= -log[ concentration ] and for this case take pH= -log[H3O+]

= -log[2.5x10^-4]

therefore pH= 3.60

The idea of pH mainly applies in the determination of the nature of various solutions to the used in the chemical analysis. The correct pH must be determined in order to get accurate results. Ionic equillibria mostly involves the calculations involving pH which is normally obtained after determination of equilibrium concentrations.

Answer:

From the Combustion formula of Organic Compounds....

Exactly 4 Moles of CO2 would make the equation balanced

So

OPTION C

4MOLES

Answer:

(C) through the atmosphere

Explanation:

Answer:

312.5 mL

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

HNO₃ + NaOH —> NaNO₃ + H₂O

From the balanced equation above,

The mole ratio of acid, HNO₃ (nₐ) = 1

The mole ratio of base, NaOH (n₆) = 1

Finally, we shall determine the volume of the base, NaOH needed for the reaction. This can be obtained as follow:

Molarity of base, NaOH (M₆) = 0.08 M

Volume of acid, HNO₃ (Vₐ) = 125 mL

Molarity of acid, HNO₃ (Mₐ) = 2 M

Volume of base, NaOH (V₆) =?

MₐVₐ / M₆V₆ = nₐ/n₆

2 × 125 / 0.80 × V₆ = 1/1

250 / 0.80 × V₆ = 1

Cross multiply

0.80 × V₆ = 250

Divide both side by 0.8

V₆ = 250 / 0.8

V₆ = 312.5 mL

Thus, the volume of the base, NaOH needed for the reaction is 312.5 mL

Answer:

false it's 24 hours long.

Answer:

the heavy one

Explanation:

the heavy one because heavy things and break things and the light one can't

Answer:

hurricane

Explanation:

Answer:

copper I oxide

Explanation:

Copper is known to form two oxides; copper I oxide and copper II oxide.

In the question we have the ions; Cu1+ and O2-. Ionic compounds are formed by a combination of ions as typified below;

Cu^+  +  O^2-   -------> Cu2O

This compound is copper I oxide

Answer:

it's the third one ozone layer depletion

Answer:

ssaasasasassdsdsdafdftrga*b*y/a la 3

Explanation:

Answer:

a) the number of protons in an atom

b) 11 protons, 11 electrons and 12 neutrons.

c) Isotope

d) yes, they still have the same number of protons and electrons.

Explanation:

b) Number of neutrons = mass number - atomic number

Atoms have the same number of electrons and protons

c) isotopes are atoms with the same number of  protons but a different number of neutrons.

Hope this helped !

Answer:

A. Heat flows from block 1 to block 2

Explanation:

Thermal or heat energy flows when objects of different temperature come in contact. Heat naturally flows from hot objects (high temperature) to cold objects (low temperature) and will keep on flowing until an equilibrium is reached.

According to this question, two blocks of metal, which are of different temperatures, are illustrated to be in contact. Block 1 is at 60°C while Block 2 is at 25°C. Block 1 is hotter than Block 2, hence, heat will flow from block 1 to block 2.

Answer:

D

Explanation:

Answer:

Natural Gas is a fossil energy source that formed deep beneath the Earth's surface. It is used in power plants to generate electricity by burning natural gas as their fuel.

Explanation: I hope this helped :)

Answer:

A molecule of natural gas is made up of carbon and hydrogen. When the hydrogen is segregated from the carbon and filled into a fuel cell, it fuses with oxygen to produce water, electricity, and heat. The carbon is released as carbon dioxide in smaller quantities than from gas turbines.

Explanation:

This is the site I got the info from :

How Natural Gas Works | Peak Oilhttps://www.peakoil.net › non-renewable › how-natural-g

Answer:

0.04 M.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

Ba(OH)₂ + H₂SO₄ —> BaSO₄ + 2H₂O

From the balanced equation above,

The mole ratio of acid, H₂SO₄ (nₐ) = 1

The mole ratio of base, Ba(OH)₂ (n₆) = 1

Finally, we shall determine the molarity of Ba(OH)₂ solution. This can be obtained as follow:

Volume of base, Ba(OH)₂ (V₆) = 93.9 mL

Volume of acid, H₂SO₄ (Vₐ) = 15.3 mL

Molarity of acid, H₂SO₄ (Mₐ) = 0.247 M

Molarity of base, Ba(OH)₂ (M₆) =?

MₐVₐ / M₆V₆ = nₐ / n₆

0.247 × 15.3 / M₆ × 93.9 = 1/1

3.7791 / M₆ × 93.9 = 1

Cross multiply

M₆ × 93.9 = 3.7791

Divide both side by 93.9

M₆ = 3.7791 / 93.9

M₆ = 0.04 M

Therefore, the molarity of the Ba(OH)₂ solution is 0.04 M

Answer:

Number of atoms is equal.

Explanation:

1 mol of anything contains NA particles.

NA is known as Avogadro's number, 6.02×10²³

We determined the moles of each compound. Both molecules are dyatomic,

H₂  → 2.02 g . 1mol / 2.016 g = 1 mol

O₂ →  32 g . 1mol / 32g = 1 mol

Both have the same amount of moles.

In conclussion, the number of atoms is the same in both samples.

Answer:

Non-renewable resources, such as coal and oil, are the primary source of power in the world, and they are used to power vehicles, factories, and homes. Although affordable, they can be harmful to the environment and are one of the notable contributors to global warming.

Explanation:

source:cfi

Answer:

94.2 g/mol

Explanation:

Ideal Gases Law can useful to solve this

P . V = n . R . T

We need to make some conversions

740 Torr . 1 atm/ 760 Torr = 0.974 atm

100°C + 273 = 373K

Let's replace the values

0.974 atm . 1 L = n . 0.082 L.atm/ mol.K . 373K

n will determine the number of moles

(0.974 atm . 1 L) / (0.082 L.atm/ mol.K . 373K)

n = 0.032 moles

This amount is the weigh for 3 g of gas. How many grams does 1 mol weighs?

Molecular weight → g/mol → 3 g/0.032 moles = 94.2 g/mol

Answer:

See Explanation

Explanation:

Let us consider the ionization of these compounds;

H3PO4 ⇔3H^+ + PO4^3-

H3BO3  ⇔3H^+ + BO3^3-

The next to consider is the type of electrolyte the both solution are; the both solutions are weak electrolytes and weak electrolytes do not ionize to a large extent.

The implication of this is that, not so much number of ions is added to the solution due to the poor ionization of these weak electrolytes. Hence, in spite of the subscript of 3, the conductivity of the solution does not significantly improve for the reason stated here quite unlike when strong electrolytes are used.

Answer:

B. The League of Nations condemned the violations but took no other action.

Explanation:

Nazi leader, Adolf Hitler violated the Treaty of Versailles by sending German military forces in Rhineland. He not only violated the Treaty of Versailles but the Locarno Pact also.

The treaty was signed in 1919 to end the war between Germany and the Allied Powers.

Even after Adolf Hitler violated the treaty, the League Nations did not take any actions.

Therefore, option B is correct.

Answer:

[tex]238.5gCuSO_4[/tex]

Explanation:

Hello there!

In this case, by considering the given chemical reaction, it is possible for us to calculate the required grams of CuSO4 by considering its molar mass of 159.6 g/mol, the given molecules of NaBr, the Avogadro's number and the 1:2 mole ratio between these two in order to set up the following stoichiometric set up:

[tex]1.80x10^{24}moleculesNaBr*\frac{1molNaBr}{6.022x10^{23}molecules NaBr}*\frac{1molCuSO_4}{2molNaBr} *\frac{159.6gCuSO_4}{1molCuSO_4}\\\\=238.5gCuSO_4[/tex]

Best regards!

Explanation:

Answer:

Creativity is a phenomenon whereby something somehow new and somehow valuable is formed. The created item may be intangible (such as an idea, a scientific theory, a musical composition, or a joke) or a physical object (such as an invention, a printed literary work, or a painting).

Scholarly interest in creativity is found in a number of disciplines, primarily psychology, business studies, and cognitive science, but also education, the humanities, technology, engineering, philosophy (particularly philosophy of science), theology, sociology, linguistics, the arts, economics, and mathematics, covering the relations between creativity and general intelligence, personality type, mental and neural processes, mental health, or artificial intelligence; the potential for fostering creativity through education and training; the fostering of creativity for national economic benefit, and the application of creative resources to improve the effectiveness of teaching and learning.



A picture of a lightbulb is associated with someone having an idea, an example of creativity.

Answer:

Uranium-235 absorbing a neutron and breaking into Barium-141,  Krypton-92 and three neutrons

Explanation:

A fission reaction is said to have occurred when an unstable nucleus is bombarded with a neutron such that it disintegrates into daughter nuclei and produces more neutrons in the process. Hence, Uranium-235 absorbing a neutron and breaking into Barium-141,  Krypton-92 and three neutrons is a fission reaction.

This fission reaction is often a self sustaining reaction. The neutrons produced in the reaction bombards more of the parent nucleus and the process continues indefinitely(chain reaction).

Control rods and moderators are used to keep the chain reaction in check.

Explanation:

(Gases and liquids )

is the answer

Gases and liquids are the states of matter that have the same volume when moved.

Hope it helps you