Pl help it’s for a grade I will give Brainly

Answer:

All these are made up of polymers.

Answer:

Molarity = 0.72M

Molality = 0.85M

Explanation:

Molarity and molality are two measures of molar concentration, and they can be calculated as follows:

Molarity = number of moles/volume of solvent

Molality = number of moles/mass (kg) of solvent

Mole = mass/molar mass

Molar mass of stilbene (C14H12) = 12(14) + 1(12)

= 168 + 12

= 180g/mol

mole of stilbene = 13/180

mole = 0.072mol

Volume = 100mL = 0.1L

molarity = 0.072/0.1

Molarity = 0.72M

Molality = number of moles ÷ mass (kg) of solvent

To get mass of solvent, we use;

Density = mass/volume

Mass = density × volume

Mass = 0.85g/mL × 100mL

Mass = 85g

Mass in kg = 85/1000 = 0.085kg

Molality = 0.072/0.085

Molality = 0.847M

Molality = 0.85M

Answer:

if its multiple, C and D, if not, C

Explanation:

brainliesttt?

One organism was ancestor of the other organism and both organisms lived around the same time is the conclusion made by scientist.

Fossil scientist are the specialists in studying the ancient fossils of animals and plants.

If fossils of two different species of very similar organisms are found in different layers of rock then it might be the possibility that one organism was ancestor of the other or both organisms lived around the same time. Because it is not necessary that if two species had the same organism then they have same behavior.

Hence, option (c) & (d) is correct.

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Answer:

I have the lowest electronegativity of the nonreactive elements. My family name is alkali metals. I am classified as a reactive metal. I have one valence electrons.

Explanation:

Electronegativity refers to the ability of the atoms of an element to attract electrons to itself. Based on their nature, non-metals are electronegative elements whereas metal are electropositive as they have a tendency to give up their electrons rather than attract electrons to themselves.

In the periodic table of elements, non-metallic character, and hence, electronegativity increases from left to right across a period, and decreases down a group. The most electropositive element is fluorine. On the other hand, electropositivity decreases across a period from left to right but increases on going down a group. Hence, the most electropositive element is Francium. This also means that Francium is the least electronegative element,

francium belong to the group 1A of the periodic table which are the most reactive metals. The family of group 1A elements are known as alkali metals. They possess only one valence electron which they easily give up to form univalent positive ions or cations. Francium is a radioactive element.

Answer:

Acids are sour in taste while bases have bitter taste for example Soap

Acids turn Blue litmus to Red While Bases turn Red litmus to Blue

Acids are Corrosive in concentrated form while bases Are non corrosive except concentrated form of NaOH and KOH

Answer:

1 . acid

a) acid are proton donors / electrons pair acceptors .

b) it have pH value < 7.

c) acids taste sour .

2 . base alkali

a) bases are proton acceptors/ electron pair donors .

b) it have pH value < 7 .

c) bases taste soupy .

Explanation:

may it helps you ....

Answer: 24

Explanation: multiply 12 with 2

Answer:

i think

D. Landmasses disrupt the spin of a typhoon while bodies of water

strengthen typhoon.

Answer:

0.347

Explanation:

Al is the limiting reagent.

Explanation:

The stoichiometry of the reaction is such that 4 moles of Al are required for every 3 moles of diatomic oxygen. This means that if the ratio of Al to diatomic oxygen is greater than 4/3, then the oxygen is the limiting reagent. If the ratio of Al to diatomic oxygen is less than 4/3, then Al is the limiting reagent.

The problem state that the ratio of Al to diatomic oxygen is

0.32

0.26

=

16

13

=

48

39

<

52

39

=

4

3

The ration of Al to diatomic oxygen is less than 4/3, so Al is the limiting reagent.

We can also see this if we ask the question "How much Aluminum" is required to completely react 0.26 moles of diatomic oxygen??

0.26

moles

O

2

×

4

moles

A

l

3

moles

O

2

≈

0.347

moles

A

l

So it would take 0.347 moles of Al to completely react with all of the oxygen, however there is only 0.32 moles of Aluminum present, so there is not enough Al to react with all of the oxygen, and so we say that the Al is the limiting reagent.

The mass of Aluminum are needed to produce 21.6 grams of Aluminum oxide (Al₂O₃) is

Mass of any element is equal to the product of its number of moles and molar mass.

For the compound, Aluminum oxide (Al₂O₃)

The atomic masses of Aluminum is 23 and oxygen is 16.

Molecular or molar mass = ( 2 × 23 ) + ( 3 × 16 ) units

M = 46 + 48 = 94 units

The mass of Aluminum in 1 mole of aluminum oxide ,46 grams in 94 grams

Mass of Aluminum in the given 21.6 g of Aluminum oxide will be;

94 grams of Aluminum oxide contains 46 grams of Aluminum.

21.6 grams of Aluminum oxide will contain ( 46 / 94 ) × 21.6 = 10.57g of Aluminum.

Therefore, 10.57g of Aluminum are needed to produce 21.6 grams of Aluminum oxide (Al₂O₃)

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Answer:

3 Shells

Explanation:

2 electrons in shell one, 8 in shell two and only 1 in shell three.

Answer:

3 shells

Explanation:

Answer:

the wax is a nonpolar substance that will not mix with polar water

Explanation:

Water is polar by due to the uneven distribution of charge between the hydrogen and oxygen. T=This automatically eliminates options 3 and 4.

Wax on the other hand is a non polar substance. Due to this non polar characteristic, it would not dissolve in water. The correct option is;

- the wax is a nonpolar substance that will not mix with polar water

Answer:

Sand is typically made mostly of varying amounts of material weathered from inland rocks and transported to the beach on the wind or in rivers, and/or shells and other hard parts precipitated out of the ocean water by marine organisms. Sand therefore records processes at a variety of timescales.

Explanation:

Answer:

Find the molar mass of each individual element, multiply that molar mass number by the element's subscript in the formula, and then add together.

Explanation:

Answer:

In the experiment performed involving the number of liquid drops that a penny can hold, 25 drops of substance X can fit in a penny while only 12 drops of substance Y can fit on another penny because, substance X is more viscous than substance Y. Thus, the intermolecular forces present in substance X are stronger than those present in substance Y.

Explanation:

Intermolecular forces (IMF) are the forces which exist between the neighboring molecules of a a substance. These forces, though weaker than intramolecular forces which acts between neighboring atoms, they still are responsible for several differences in the physical properties of substances with comparatively similar molecular masses.

The three major types of intermolecular forces are, hydrogen bonding, dipole–dipole interactions and  London dispersion forces.

The existence of intermolecular forces in molecules of substances results in increase in melting and boiling points, surface tension,  capillary action, viscosity, as well as surface area of substances,

Viscosity, which is the resistance to flow offered by a liquid increases with increase in the intermolecular forces between the molecules of a liquid.

In the experiment performed involving the number of liquid drops that a penny can hold, 25 drops of substance X can fit in a penny while only 12 drops of substance Y can fit on another penny because, substance X is more viscous than substance Y. Thus, the intermolecular forces present in substance X are stronger than those present in substance Y.

Answer:

B. CdSO4(aq) + K2S(aq) → CdS(s) + K2SO4(aq)

Explanation:

A precipitate reaction is when a solid forms, so in this case CdS is the precipitate.

Answer:

Charge

Explanation:

A surplus (having "extra") or deficit (having "fewer") of electrons possessed by an object. A charge can cause attractive or repulsive forces which can be observed in some cases (e.g. pith balls, bits of plastic).

Answer:

21.614 grams are found in [tex]6.5 \times 10^{22}[/tex] molecules of caffeine.

Explanation:

The chemical formula for caffeine is [tex]C_{8}H_{10}N_{4}O_{2}[/tex], the molar weight of caffeine is:

[tex]M = 8\cdot \left(12.011\,\frac{g}{mol} \right) + 16\cdot \left(1.008\,\frac{g}{mol} \right)+4\cdot \left(14.007\,\frac{g}{mol} \right)+2\cdot \left(15.999\,\frac{g}{mol} \right)[/tex]

[tex]M = 200.242\,\frac{g}{mol}[/tex]

According to Avogadro's Law, a mol of caffeine contains [tex]6.022\times 10^{23}[/tex] molecules. The number of grams contained in [tex]6.5 \times 10^{22}[/tex] molecules is determined by simple rule of three:

[tex]x = \frac{6.5\times 10^{22}\,molecules}{6.022\times 10^{23}\,molecules} \times 200.242\,g[/tex]

[tex]x = 21.614\,g[/tex]

21.614 grams are found in [tex]6.5 \times 10^{22}[/tex] molecules of caffeine.

Answer:

The IUPAC name of CH3 – CH2 – CH2 – CH=CH2 is Pent-1-ene.

The highest ionization energy of alkaline earth metal is calcium. Therefore, option (A) is correct.

The ionization energy can be described as the minimum energy that an electron has to absorb to come out of the effect of the nucleus of a gaseous atom or ion.

It tells about the reactivity of chemical compounds and determines the strength of chemical bonds. The units of ionization energy are electronvolts or kJ/mol.

Ionization energy measures the difficulty in removing an electron from an atom or ion and the loss of electron occurs in the ground state of the chemical species.

According to the general configuration of alkaline earth metals, they contain two electrons in their valence shell. The atomic size of alkaline earth metals increases as we move down the group. The electronegativity and effective nuclear charge of alkaline earth metals decrease.

The electron can easily be lost from the atom as we move down the group. Therefore, calcium present at the top of the group has the highest ionization energy.

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Answer:

The answer is intrusive igneous and extrusive igneous.

Explanation:

I’ve done the question on A P E X

Answer:

2385.49 grams of cobalt.

Explanation:

1. Convert 40.48 moles of Co (cobalt) into grams (mass):

The molar mass of cobalt is 58.933195 g/mol.

[tex]40.48 mol Co = \frac{58.93 g/mol}{1 mol Co} = 2385.49 g[/tex]

Answer: It will get higher

Explanation: it’ll get higher because the pressure will increase

Answer: the water avaperatid

because of the heat lamp

hope this helps

Explanation:

Answer:

it will gain electrons to fill its outer shell

Explanation:

This element is boron which has 5 electrons.