Based on his education what is amazing about issac Newton’s great abilities in math and science

How much of a radioactive parent isotope will remain after three half-lives have passed?

Leona [35]

After 1 half life, 1/2
After 2 half lives, 1/4
After 3 half lives, 1/8

6 0

3 years ago

The whiye pigment TiO2 is prepared by the reaction of titanium tetrachloride, TiCl4, with water vapor in the gas phase:

omeli [17]

Answer:

$\boxed{\text{62.1 kJ}}$

Explanation:

The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is

$\Delta_{\text{r}}H^{\circ} = \sum \Delta_{\text{f}} H^{\circ} (\text{products}) - \sum\Delta_{\text{f}}H^{\circ} (\text{reactants})$

TiCl₄(g) + 2H₂O(g) ⟶ TiO₂(s) + 4HCl(g)

ΔH°f/kJ·mol⁻¹: -763.2 -241.828 -939.7 -92.307

$\begin{array}{rcl}\Delta_{\text{r}}H^{\circ} & = & [-939.7 + 4(-92.307)] - [-763.2 + 2(-241.828)\\& = & [-939.7 - 369.228] - [-763.2 - 483.656]\\& = & -1308.928 + 1246.856\\& = & \mathbf{-62.1}\\\end{array}\\\text{The amount of heat evolved is } \boxed{\textbf{62.1 kJ}}$

5 0

3 years ago

What is a cation and where can you find it on the periodic table?

Maslowich

Answer:

A cation is an ion with fewer electrons than protons. Therefore, it has a positive charge. The electric charge on a proton is equal in amount to the charge on an electron. Anions are atoms or radicals (groups of atoms), that have gained electrons. Since they now have more electrons than protons, anions have a negative charge. Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions (e.g. oxygen, carbon, sulfur).

Explanation:

An anion and cation cannot be specifically found on the periodic table.

4 0

2 years ago

Twenty irregular pieces of an unknown metal have a collective mass of 28.225 g. When carefully placed in a graduated cylinder th

Lelechka [254]

Explanation:

Use the density formula to determine the volume of the piece of metal.

density

=

mass

volume

Rearrange the equation to isolate volume.

volume

=

mass

density

volume

=

147

g

7.00

g

mL

=

21.0 mL

The final volume in the cylinder after adding the piece of metal is

20.0 mL

+

21.0 mL

=

41.0 mL

8 0

3 years ago

Control of Blood pH by respiratory rate.

nata0808 [166]

Answer:

A) During this procedure ( hypoventilation ) The CO2 in the arterial blood vessels and the lungs increases and this drives the PH level in the system lower, and the equilibrium will shift to the right. this is because the Blood-PH level is controlled by CO2 - bicarbonate buffer system

B) The blood PH may rise to 7.60 during Hyperventilation because the removal of CO2 from the lungs causes the increase in $H^+$ which is directly proportional to the increase in Blood PH levels

C) Hyper ventilation before a dash would be useful because it will remove excessive Hydrogen ions and and raise the Blood PH levels in preparedness of the production of acids like Lactic acid

Explanation:

A) During this procedure ( hypoventilation ) The CO2 in the arterial blood vessels and the lungs increases and this drives the PH level in the system lower, and the equilibrium will shift to the right. this is because the Blood-PH level is controlled by CO2 - bicarbonate buffer system

$CO_{2} +H_{2} O$ ⇄ $H^+ + HCO^-_{3}$

B) The blood PH may rise to 7.60 during Hyperventilation because the removal of CO2 from the lungs causes the increase in $H^+$ which is directly proportional to the increase in Blood PH levels

C) Hyper ventilation before a dash would be useful because it will remove excessive Hydrogen ions and and raise the Blood PH levels in preparedness of the production of acids like Lactic acid

6 0

3 years ago