True or False: Passive transport occurs when molecules move from an area of low concentration to high concentration.

Quartz,SiO2,contains 46.7% silicon. What mass of silicon is present in 381 g of quartz?

swat32

Answer:

119 g.

Explanation:

4 0

3 years ago

Describe how elements of different electronegativities can share electrons unequally, leading to the formation of a polar covale

Nesterboy [21]

A polar covalent bond is a covalent bond in
which the atoms have an unequal attraction for
electrons and so the sharing is unequal. ... The
atom with the greater electronegativity acquires
a partial negative charge, while the atom with
the lesser electronegativity acquires a partial
positive charge.

here you go

6 0

2 years ago

A sample of gas initially occupies 4.25 L at a pressure of 0.850 atm at 23.0°C. What will the volume be if the temperature is ch

Akimi4 [234]

Answer:

$2.31\text{ L}$

Explanation:

Here, we want to calculate the final volume

We use the general gas equation here:

$\frac{P_1V_1}{T_1}\text{ = }\frac{P_2V_2}{T_2}$

P1 is the initial pressure which is 0.850 atm

V1 is the initial volume which is 4.25 L

T1 is the initial temperature which is (23 + 273.15 = 296.15 K)

P2 is the final pressure which is 1.50 atm

V2 is the final volume which is unknown

T2 is the final temperature (11.5 + 273.15 = 284.65 K)

Substituting the values, we have:

$\begin{gathered} \frac{0.850\text{ }\times4.25}{296.15}\text{ = }\frac{1.50\times V_2}{284.65} \\ \\ V_2\text{ = }\frac{284.65\text{ }\times0.850\times4.25}{1.5\times296.15} \\ \\ V_2\text{ = 2.31 L} \end{gathered}$

6 0

1 year ago

When Mrs. Green describes the physical properties of matter she said that physical properties often concern changes in state. On

dedylja [7]

Properties of matter can be broadly classified into two categories:

-Physical properties, these usually involve a change in the state of matter

-Chemical properties. these involve a change in the chemical composition of matter.

Now, physical properties can be further classified as:

Extensive: these depend on the amount of the substance, eg: mass, volume

Intensive: these do not depend on the amount of the substance eg: density, color, melting point, boiling point

A physical property that does not describe a change in state is color. For example: copper sulfate is a compound which is a blue in color. Thus, color provides information which describes the appearance of matter. In contrast, properties like melting or boiling point suggests a change in the state of the substance.

3 0

3 years ago

Which set of numbers gives the correct possible values of I for n = 2?

Marysya12 [62]

Answer:

0,1

Explanation:

There are four quantum numbers:

Principal quantum number (n)

Azimuthal quantum number (l)

Magnetic quantum number (ml)

Spin quantum number (ms)

All these four quantum numbers gives complete information about an electron like its spin, shells, subshells and orbitals.

For example:

If n=2 than possible sets of quantum numbers are:

Azimuthal quantum number (l)

The azimuthal quantum number describe the shape of orbitals. Its value for s, p, d, f... are 0, 1, 2, 3. l= n-1

(n-1)

2-1 = 1

For n=2 there are two subshell s and p.

s = 0

p= 1

Magnetic quantum number (ml)

It describe the orientation of orbitals. Its values are -l to +l. For l=1 the ml will be -1 0 +1

Spin quantum number (ms)

The spin quantum number tells the spin of electron either its clock wise (+1/2) or anti clock wise (-1/2).

If the electron is added in full empty orbital its spin will be +1/2 because it occupy full empty. If electron is already present and another electron is added then its spin will be -1/2.

4 0

3 years ago