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3 years ago

Why can’t straw be made into gold

2 answers:

6 0

Grains contain gold in forms that seem tailor-made for industrial use. Rumpelstiltskin, the fairy-tale rogue who spun straw into gold, has nothing on Miguel Yacaman and Jorge Gardea-Torresdey. The gold appears as particles mere billionths of a meter wide

fiasKO [112]3 years ago

4 0

It is very hard to do so

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Which are homogeneous mixtures? check all that apply

marishachu [46]

Answer:

isk tbh,

Explanation:

5 0

3 years ago

Read 2 more answers

According to Newton’s second law of motion, when an object is acted on by an unbalanced force, how will that object respond? It

otez555 [7]

Answer:

C) It will accelerate.

Explanation:

According to Newton’s second law of motion, when an object is acted on by an unbalanced force, it will accelerate.

An unbalanced force will change the speed or direction (or both) of an object. A change in speed and/or direction is acceleration.

A) is wrong. The object will stop moving only if there is a balanced force in the opposite direction.

B) is wrong. The object will decrease speed only if the unbalanced force has a component opposite to the direction of motion.

d) is wrong. The object will increase speed only if the unbalanced force has a component in the direction of motion.

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3 years ago

Mature elephants consume an average of 600 pounds of food per day. If an elephant

MAXImum [283]

Answer:

$\large \boxed{\text{4 600 000 kg or 4600 Mg}}$

Explanation:

1. Calculate the adult life

If the elephant is an adult from its 10th birthday until the day before its 56th birthday, its

Adult life = 55 - 10 + 1 = 46 yr

2. Convert years to days

$\text{Adult life} = \text{46 yr} \times \dfrac{\text{365.25 da}}{\text{1 yr}} = \text{16 800 da}$

3. Convert days to pounds of feed

$\text{Feed} = \text{16 800 da} \times \dfrac{\text{600 lb}}{\text{1 da}} = 1.01 \times 10^{7} \text{ lb}$

4. Convert pounds to kilograms and megagrams

$\text{Feed} =1.01 \times 10^{7} \text{ lb} \times \dfrac{\text{1 kg}}{\text{2.20 lb}} =\textbf{4 600 000 kg} = \textbf{4600 Mg}\\\\\text{The elephant will eat $\large \boxed{\textbf{4 600 000 kg or 4600 Mg}}$ of food.}$

Note: The answer can have only two significant figures because that is all you gave for age of the elephant.

5 0

4 years ago

The standard enthalpy of formation of BrCl(g) is 14.7 kJmol-1 . The standard enthalpies for the atomization of Br2(l) and Cl2(g)

natita [175]

Explanation:

Equation of the reaction:

Br2(l) + Cl2(g) --> 2BrCl(g)

The enthalpy change for this reaction will be equal to twice the standard enthalpy change of formation for bromine monochloride, BrCl.

The standard enthalpy change of formation for a compound,

ΔH°f, is the change in enthalpy when one mole of that compound is formed from its constituent elements in their standard state at a pressure of 1 atm.

This means that the standard enthalpy change of formation will correspond to the change in enthalpy associated with this reaction

1/2Br2(g) + 1/2Cl2(g) → BrCl(g)

Here, ΔH°rxn = ΔH°f

This means that the enthalpy change for this reaction will be twice the value of ΔH°f = 2 moles BrCl

Using Hess' law,

ΔH°f = total energy of reactant - total energy of product

= (1/2 * (+112) + 1/2 * (+121)) - 14.7

= 101.8 kJ/mol

ΔH°rxn = 101.8 kJ/mol.

8 0

4 years ago

What was the result of collisions between the early Earth and other, smaller protoplanets?

RoseWind [281]

The trajectory of their motion knocked the Earth into a different orbit.

3 0

4 years ago