6. List the following particles in size order, from biggest to smallest?

The temperature in a town started out at 55 degrees. By the end of the day the temperature dropped to -6 degrees.

garik1379 [7]

Answer:

The choice of the answer is fourth option that is -61 degrees.

Therefore the temperature drop is -61°Centigrade.

Explanation:

Given:

The temperature in a town started out at 55 degrees

Start temperature = 55°Centigrade. (Initial temperature)

End of the Day = -6°Centigrade. (Final temperature)

To Find:

How far did the temperature drop?

Solution:

We will have,

$\textrm{Temperature drop}=\textrm{Final temperature}-\textrm{Initial temperature}$

Substituting the above values in it we get

$\textrm{Temperature drop}=-6-55\\\\\therefore \textrm{Temperature drop}=-61\° centigrade$

Therefore the temperature drop is -61°Centigrade.

4 0

4 years ago

vaieri [72.5K]

Answer:

Options a,b, c and d are correct

Explanation:

From the diagram attached in the picture below, They both have steroid nucleus since they have functional groups (such as the methyl and the ketone groups) that are spatially attached. It can also be deduced that both structures have three (3) ketone groups (CO/C=O), two (2) methyl groups (CH₃) and two (2) hydroxyl groups (OH). Hence, options a, b,c and d are correct.

However, cortisone has one (1) double bond while prednisone has two (2) double bonds.

8 0

3 years ago

20 cubic inches of a gas with an absolute pressure of 5 psi is compressed until its pressure reaches 10 psi. What's the new volu

belka [17]

10 cubic inches
We will use Boyle's law that states that for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional.
P1 V1 = P2 V2
Where
P1 is initial pressure = 5 psi
V1 is initial volume = 20 cubic inch
P2 is final pressure = 10 psi
V2 is final volume = unknown
V2 = P1,V1 / P2
V2 = 20 × 5 / 10
V2 = 100/10
V2 = 10 cubic inches

7 0

3 years ago

What are some complex impurities found in water that are hard to detect and remove? How are they removed and detected? Please an

liubo4ka [24]

This are my answers to your quesion

When working in laboratories and hospitals, it’s crucial that any contaminants found in water are removed immediately, before they cause any damage.

Each impurity carries its own risks to chemical and biological research, not to mention the detrimental effect they cause to the quality of pure water. Here we discuss the 8 main types of water contaminants, and how they can be prevented.

1. Microorganisms

Bacteria, algae and fungi all regularly interfere with sterile research applications. Bacteria can adversely influence cell and tissue culture by competing at enzyme-active sites on substrates.

If free-floating bacteria form biofilms on surfaces, they can be extremely difficult to remove. These biofilms can grow for several years, spontaneously releasing bursts of bacteria, along with their associated endotoxins and nucleases.

These nucleases then break down DNA and RNA in samples, and the endotoxins will have a negative effect on the growth and function of cells.

2. Viruses

Viruses – referred to as non-living nucleic acids – adversely affect tissue and cell growth. They’re extremely small, with most of them falling between 0.01 – 0.3 microns, and they can survive for long periods of time. Once they’ve been spotted in water, they should be removed as soon as possible.

3. Pyrogens

For mammalian cell cultures, and the preparation of solutions or devices that will later have contact with humans and other mammals, it’s crucial that the water used is pyrogen-free.

The most significant component of pyrogens – a form of endotoxin – is lipopolysaccharides (LPS), which is derived from Gram-negative bacteria walls. If LPS gets into the blood or spinal fluid, it can be toxic and cause a fever.

4. Dissolved Inorganic Ions

Silicates, chlorides, calcium, fluorides, magnesium, phosphates, bicarbonates, sulphates, nitrates and ferrous compounds are all forms of dissolved inorganic ions.

The instability in water caused by these ions will negatively influence chemical and biological reactions. Results include the formation of protein-protein and protein-lipid interaction, altering enzymatic activity, and delaying the growth of cells and tissue.

5. Dissolved Organic Compounds

These are derived from animal and plant decay, in addition to any human activities that involve the introduction of alcohol, protein, pesticides, chloramine, herbicides or detergents into the environment.

Dissolved organic compounds interfere with high performance liquid chromatography (HPLC), gas chromatography and fluoroscopy.

6. Dissolved Gases

Water contains naturally dissolved carbon dioxide, nitrogen and oxygen, but these gases can alter the pH of lab water, which upsets the ionic balance. Concentrations of oxygen and nitrogen can affect the rate of biochemical reactions; and high concentration of dissolved gases can cause a bubble formation, which obstructs the flow through chromatography columns and micro-channels.

Dissolved carbon dioxide raises water acidity, reducing the capacity of ion exchange resins in DI systems.

7. Suspended Particles

When large suspended particles of clay, sand, silt or vegetation between 1 – 10µm are found in water, they cause turbidity and settle at the bottom.

Suspended particles can foul reverse osmosis membranes, filters and chromatography columns, especially if the system stems from a reservoir or tank within the building.

8. Colloidal Particles

Colloidal particles are much smaller than suspended particles, at just 0.01 – 1.0µm, and they don’t settle.

Colloidal particles regularly interfere with analytical techniques, and bypass ion exchange resins, which result in lower resistivity in DI water.

How to Prevent Contaminants

The main way to prevent and remove contaminants are through water purification systems. Different technologies have been created, each specialising in the removal of specific contaminants.

For example, whilst the process of distillation won’t remove ionised gases, inorganic ions or dissolved non-ionised gases, they will filter out bacteria and pyrogens.

Reverse osmosis (RO) is hailed as one of the most effective ways of removing contaminants, as this process removes up to 99% of impurities in water. Dissolved organics and ionics, suspended impurities, bacteria and pyrogens are all removed from water when RO is used.

To conclude, contaminants can be very damaging to water. Once found, they should be removed as soon as possible, using the most effective form of water purification technology.

4 0

3 years ago

Why in anaerobic conditions is nadh oxidized by lactate dehydrogenase.

stiv31 [10]

Answer:

It is in the oxidation of NADH to NAD + that lactate dehydrogenase (LDH) plays an important role. LDH catalyzes the following reaction The lactate then diffuses out of the cell and the NAD + is used to continue glycolysis.It is in this manner that the cell continues to produce energy under anerobic conditions.

Explanation:

4 0

3 years ago