Why did most scientists reject Wegner's theory for nearly a half century?

What are facts or characteristics about acid?

noname [10]

Acids are ionic compounds (a compound with a positive or negative charge) that break apart in water to form hydrogen ion (H+). Characteristics of acid: Acid taste sour. Acids also react strongly to metals, generally with the evolution of hydrogen gas (Eg: Zn + HCI). Also strong acids are dangerous and can burn your skin off. Acids change litmus red. Acids become less acidic when mixed with bases. An acid has Ph scale of under 7.

8 0

3 years ago

An organism's _______ describes its genetic composition. An organism's _______ describes its appearance or observable characteri

Kisachek [45]

B.
<span>genotype; phenotype

</span><span>Genetic variation determines inherited differences between individuals . Our height or eye color are inherited from our parents, but our phenotype is also affected by environment such as the food we eat (diet), drugs we take, toxins surrounding us, climate, location, culture, physical accidents and lifestyle.</span>

7 0

3 years ago

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An aluminum cylinder has a radius of 3.2 cm and a length of 8.6 cm. What is the mass of the aluminum cylinder if aluminum has a

Hatshy [7]

Answer:

750g of Aluminum

Assuming 8.6 cm lenth is the height of the cylinder. The volume of a cylinder is: V = $\pi$ *r^2*h

V = 3.14cm x 10.24cm x 3.6cm

V = 280cm^3

Now density = mass/volume

2.7g/cm^3 = mass/280cm^3

2.7g/cm^3 x 280cm^3 = mass/<u>280cm^3</u> x <u>280cm^3</u>

= 750g of Aluminum

5 0

3 years ago

How many milliliters are in 425 g of bromine if the density of bromine is 3.12 g/cm3

arlik [135]

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

$volume = \frac{mass}{density} \\$

From the question

mass = 425

density = 3.12 g/cm³

We have

$volume = \frac{425}{3.12} \\ = 136.2 \: \: {cm}^{3}$

Since cm³ = mL

We have the final answer as

Hope this helps you

7 0

3 years ago

Use the data given below to construct a Born-Haber cycle to determine the second ionization energy of Ca. Δ H°(kJ) Ca(s)→Ca(g) 1

Drupady [299]

Answer : The value of second ionization energy of Ca is 1010 kJ.

Explanation :

The formation of calcium oxide is,

$Ca(s)+\frac{1}{2}O_2(g)\overset{\Delta H_f}\rightarrow CaO(s)$

$\Delta H_f^o$ = enthalpy of formation of calcium oxide = -635 kJ

The steps involved in the born-Haber cycle for the formation of $CaO$ :

(1) Conversion of solid calcium into gaseous calcium atoms.

$Ca(s)\overset{\Delta H_s}\rightarrow Ca(g)$

$\Delta H_s$ = sublimation energy of calcium = 193 kJ

(2) Conversion of gaseous calcium atoms into gaseous calcium ions.

$Ca(g)\overset{\Delta H_I_1}\rightarrow Ca^{+1}(g)$

$\Delta H_I_1$ = first ionization energy of calcium = 590 kJ

(3) Conversion of gaseous calcium ion into gaseous calcium ions.

$Ca^{+1}(g)\overset{\Delta H_I_2}\rightarrow Ca^{+2}(g)$

$\Delta H_I_2$ = second ionization energy of calcium = ?

(4) Conversion of molecular gaseous oxygen into gaseous oxygen atoms.

$O_2(g)\overset{\Delta H_D}\rightarrow OI(g)$

$\frac{1}{2}O_2(g)\overset{\Delta H_D}\rightarrow O(g)$

$\Delta H_D$ = dissociation energy of oxygen = $\frac{498}{2}=249kJ$

(5) Conversion of gaseous oxygen atoms into gaseous oxygen ions.

$O(g)\overset{\Delta H_E_1}\rightarrow O^-(g)$

$\Delta H_E_1$ = first electron affinity energy of oxygen = -141 kJ

(6) Conversion of gaseous oxygen ion into gaseous oxygen ions.

$O^-(g)\overset{\Delta H_E_2}\rightarrow O^{2-}(g)$

$\Delta H_E_2$ = second electron affinity energy of oxygen = 878 kJ

(7) Conversion of gaseous cations and gaseous anion into solid calcium oxide.

$Ca^{2+}(g)+O^{2-}(g)\overset{\Delta H_L}\rightarrow CaO(s)$

$\Delta H_L$ = lattice energy of calcium oxide = -3414 kJ

To calculate the overall energy from the born-Haber cycle, the equation used will be:

$\Delta H_f^o=\Delta H_s+\Delta H_I_1+\Delta H_I_2+\Delta H_D+\Delta H_E_1+\Delta H_E_2+\Delta H_L$

Now put all the given values in this equation, we get:

$-635kJ=193kJ+590kJ+\Delta H_I_2+249kJ+(-141kJ)+878kJ+(-3414kJ)$

$\Delta H_I_2=1010kJ$

Therefore, the value of second ionization energy of Ca is 1010 kJ.

6 0

3 years ago