Select all of the statements that correctly describe DNA structure:

Chemistry

1 answer:

GalinKa [24]2 years ago

3 0

Answer:

Hydrogen bonds will hold two DNA strands together.
The sugars and phosphate groups are located on the exterior of the helix.
Base pairing will always be between a purine base and a pyrimidine base.

<em>I hope this helps you</em>

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Write an interesting good presentation of acid and base

aleksley [76]

these are sour in taste
corrosive in nature
the turn blue litmus to red when litmus paper is dipped into it
we also eat acids like citric acid in our daily life

bitter in taste
soapy to touch
turn red litmus to Blue
we use bases like milk of magnesia and antacid in our daily life

Hope it helps u

5 0

3 years ago

Explain why gasoline is insoluble in water

SVETLANKA909090 [29]

Answer:

it's not

Explanation:

gasoline is not soluble in water in gasoline is a complex mixture of nonpolar compounds such as long-chain hydrocarbons etc water is a polar molecule as a result of the gasoline molecules cannot enter water and borla solution

4 0

3 years ago

PLEASE ASAP

Kitty [74]

Choice c - eats away other materials

7 0

3 years ago

What masses of iron(iii) oxide and aluminum must be used to produce 15.0 g iron? what is the maximum mass of aluminum oxide that

defon

1) Chemical reaction:

Fe2O3 + 2Al ---> Al2O3 + 2Fe

2) molar ratios

1 mol Fe2O3 : 2Al : 1 mol Al2O3 : 2 mol Fe

3) Convert 15.0 g of iron into moles

atomic mass Fe = 55.8 g/mol

moles = mass in grams / atomic mass = 15.0 g / 55.8 g/mol = 0.269 mol

4) Use proportions to determine the moles of Fe2O3, Al, and Al2O3

a) 1mol Fe2O3 / 2 mol Fe = x / 0.269 mol Fe

x =

=> x = 0.269 mol Fe * 1 mol Fe2O3 / 2 mol Fe = 0.134 mol Fe2O3

b) 2 mol Al / 2 mol Fe = x / 0.269 mol Fe

=> x = 0.269 mol Al

c) 2 mol Fe / 1 mol Al2O3 = 0.269 mol Fe / x

=> x = 0.269 mol Fe * 1 mol Al2O3 / 2 mol Fe

x = 0.134 mol Al2O3

5) Convert moles to grams

a) Fe2O3

molar mass Fe2O3 = 2* 55.8 g/mol + 3*16g/mol = 159.6 g/mol

mass = molar mass * number of moles

mass = 159.6 g/mol * 0.134 mol = 21.4 g

b) Al

atomic mass = 27.0 g/mol

mass = number of moles * atomic mass = 0.269 mol * 27.0 g/mol = 7.26 g

c) Al2O3

molar mass = 2 * 27.0 g/mol + 3*16.0 g/mol = 102.0g/mol

mass Al2O3 = numer of moles * molar mass = 0.134 mol * 102.0 g/mol = 13.7 g

Answers:

21.4 g Fe2O3

7.26 g Al

13.7 g Al2O3

6 0

3 years ago

Which example is a long-term environmental change? La Niña El Niño climate change small asteroid impact

anyanavicka [17]

The correct answer is C. Climate change

Explanation:

Long-term environmental changes occur as major events affect the environment and ecosystems indefinitely. These events differ from short-term environmental changes because the effect of short-term environmental changes is mainly temporary. Also, long-term changes are usually gradual.

Climate change is an example of long-term environmental changes because this implies indefinite and major changes in weather patterns and ecosystems. For example, it is believed climate change will decrease the amount of ice in Earth, change sea level, and lead to the extinction of dozens of species. This does not occur with events such as el niño or a small asteroid impact that affect the environment for a short time and do not imply major changes.

3 0

3 years ago