What are the components of DNA? A. ribose sugar, cytosine, guanine, adenine, thymine, and phosphate group

B. ribose sugar, cytosine, guanine, adenine, uracil, and phosphate group

C. deoxyribose sugar, cytosine, guanine, adenine, thymine, and phosphate group

D. deoxyribose sugar, cytosine, guanine, adenine, uracil, and phosphate group

Answer:

¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e

Explanation:

Key statement;

The first transuranium element neptunium, NpNp, was prepared by bombarding U−238U−238 with neutrons to form a neptunium atom and a beta particle.

This is the beta particle;  ⁰₋₁e

¹₀n+ ²³⁸₉₂U → Np + ⁰₋₁e

The mass number of Np;

1 + 238 = Np + 0

Np = 239

The atomic number of Np;

0 + 92 = Np + (-1)

92 + 1 = Np

Np = 93

The equation is given as;

¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e

Answer:

2 FeBr₃(aq) + 3 (NH₄)₂CO₃(aq) = Fe₂(CO₃)₃(s) + 6 NH₄Br(aq)

Explanation:

Aqueous solutions of iron(III) bromide and ammonium carbonate react. This is a double displacement reaction that gives place to ammonium bromide and iron (III) carbonate. Iron (III) carbonate is insoluble so it precipitates. The corresponding molecular equation is:

2 FeBr₃(aq) + 3 (NH₄)₂CO₃(aq) = Fe₂(CO₃)₃(s) + 6 NH₄Br(aq)

Answer: b

A change of state is a reversible process.

Answer:

Ea =22542.6

Explanation:

The rate constant k is affected by the temperature and this dependence may be represented by the Arrhenius equation:

where the pre-exponential factor A is assumed to be independent of temperature, R is the gas constant, and T the temperature in K. Taking the natural logarithm of this equation gives:

ln  k = ln A - Ea/(RT)

or

ln  k = -Ea/(RT) + constant

or

ln  k = -(Ea/R)(1/T) + constant

These equations indicate that the plot of ln k vs. 1/T is a straight line, with a slope of -Ea/R. These equations provide the basis for the experimental determination of Ea.

now applying the above equation in the problem

we can write that

solve for Ea:

Ea = R[Ln(k2/k1)] / [(1/T1) - (1/T2)]

but k_2 = 2 k_1, hence:

Ea = (8.314 J/moleK)[ln(2)] / [(1/273+45) - (1/273+73)]

Ea =22542.6

Answer:

The activation energy for this reaction is 22.6 kJ/ mol

Explanation:

Step 1: Data given

Rate constant doubles when Temperature goes from 45.0 °C to 73.0 °C

R = 8.314 J/K*mol

Step 2: Calculate the activation energy

Log (k2/k1) = Ea / 2.303R *((1/T1) - (1/T2))

⇒ with k1 = initial rate constant

⇒ with k2 = rate constant after doubled = 2k1

⇒ T1 = initial temperature = 45.0 °C = 318 Kelvin

⇒ T2 = Final temperature = 73.0 °C = 346 Kelvin

log (2) = Ea / (2.303*8.314) *((1/318) - (1/346))

log(2) = Ea / (2.303*8.314) * 0.00025448

Ea = 22649 J/mol = 22.6 kJ/mol

The activation energy for this reaction is 22.6 kJ/ mol

Considering the formation of a chemical formula, the chemical formula is Li₂O.

Ionic compounds

Cations (positivelycharged ions) and anions (negatively charged ions) combine to form ionic compounds, which must be electrically neutral. Therefore, the cations and anions must combine in such a way that the net charge contributed by the total number of cations exactly cancels the net charge contributed by the total number of anions.

Formation of a chemical formula

To form the chemical formula:

• It is first necessary to place the chemical symbol of the element that is a cation, and then the negative part (anion).
• Since the net charge of the compound formed must be zero (that is, add zero), when cations and anions with different charges are joined, it is necessary to cross them and place them as subscripts of the other element. In this way, balanced loads are obtained, that is, the algebraic sum is equal to zero.

Chemical formula in this case

Lithium (Li) has a charge of +1, and oxygen has a charge of -2. Taking into account the above, the chemical formula is Li₂O.

Answer:

Lithium formula=Li+

Oxygen formula=O2(2-)

Explanation:

Quick note: These kinds of formula are really easy to google. Next time, google the chemical name, include the charge and include "formula" and you should get the answer.