Which of the following choices about teenagers and sex is true?

a. Over half of teenagers have sexual intercourse.

b. Teenagers who have sexual intercourse are more likely to use protection.

c. Teenage sex is more likely to involve coercion.

d. All of the choices are correct.

collision theory

Explanation:

Collision theory, theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another.

Answer:Solar flares have been known to affect electronic communication because their energy stirs up the Earth's upper atmosphere.

Explanation:

Answer:

Nonmetals

Explanation:

Nonmetals typically lacks the metallic bonding which allows substances to exhibit metallic properties that confers special properties on them.

Nonmetals lacks these properties but metalloids are able to show some of the properties under certain and special conditions.

Answer:

icicle becausit sounds right

Explanation:

icicles because it sounds right

Answer:

6.07 g.

Explanation:

Hello!

In this case, given the chemical reaction:

[tex]Zn + H_2CO_3 \rightarrow ZnCO_3 + H_2[/tex]

We first need to compute the moles of each reactant considering their molar masses:

[tex]n_{Zn}=4gZn*\frac{1molZn}{65.38 gZn} =0.0612molZn\\\\n_{H_2CO_3}=3gH_2CO_3*\frac{1molH_2CO_3}{62.03 gH_2CO_3} =0.0484molH_2CO_3[/tex]

Now, compute the mass of zinc carbonate yielded by each reactant in order to pick out the correct limiting reactant:

[tex]n_{ZnCO3}^{by\ Zn} = 0.0612molZn*\frac{1molZnCO3}{1molZn}*\frac{125.4 gZnCO3}{1molZnCO3}=7.67gZnCO3 \\\\n_{ZnCO3}^{by\ H_2CO3} = 0.0484molH_2CO3*\frac{1molZnCO3}{1molH_2CO3}*\frac{125.4 gZnCO3}{1molZnCO3}=6.07gZnCO3[/tex]

Thus, we conclude carbonic acid is the limiting reactant as it produces the fewest grams of product and therefore the yielded mass of zinc carbonate product 6.07 g.

Best regards.

Answer:

12 moles of H₂SO₄

Explanation:

The reaction equation is given as;

          3H₂SO₄  +  2Fe⁻  →  Fe₂(SO₄)₃  +  3H₂

From the balanced reaction equation:

    Number of moles of Fe = 8moles  

So;

           2 mole of Fe will react with 3 moles of H₂SO₄

           8 moles of Fe will therefore yield [tex]\frac{8 x 3}{2}[/tex]   = 12 moles of H₂SO₄

Answer:

11x³ – 2x² + 3x + 11

Explanation:

From the question given above:

We are to find the sum of:

4x³ + 2x² – 4x + 3 and 7x³ – 4x² + 7x + 8

To add the above polynomials together we must recognise that we can only add like terms together. The sum of the above polynomials can be obtained as follow:

. 4x³ + 2x² – 4x + 3

+ 7x³ – 4x² + 7x + 8

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

= 11x³ – 2x² + 3x + 11

Thus, the sum of 4x³ + 2x² – 4x + 3 and 7x³ – 4x² + 7x + 8 is 11x³ – 2x² + 3x + 11

Answer:

0.4 m/s2 towards the West.

Explanation:

MARK ME THE BRAINLIES PLEASE!!

Answer:

A higher hill will give more potential energy, and a lower hill will give less.

Explanation: Gravitational potential energy is the energy stored in an object based on its height and mass.  The potential energy in an object increases as its elevation increases.

Answer:

heterozygous

Answer:

There are 4 oxygen and 1 sulfur.

Explanation:

Calcium sulfate is made up of 1 calcium, 1 sulfur and 4 oxygen.

Answer:

Group 1 elements tend to react with group Group 17 elements to form alkyl halide.

The balanced equation :

4Fe + 3O₂⇒ 2Fe₂O₃

Given

Rust reaction

Required

Balanced equation

Solution

Reaction

Fe + O₂⇒ 2Fe₂O₃

For a simple equation where one of the reaction coefficients is known, we can immediately add the corresponding coefficient using the principle that the number of atoms of the components in the reactants and products is the same.

In the above reaction :

Fe, left=1, right = 4, so coefficient in the left=4

O, left=2, right = 6, so coefficient in the left=3

Answer:

Potential energy = mass(velocity)

Explanation:

It is the formula used to explain how to find the answer for potential energy

Relative humidity is the percentage of what it can hold. Humidity is the measure of the amount of water vapor it can hold.

hope this helps ^^

Answer:

502.9 nm

Explanation:

Energy to break to the bond of carbon-iodine is not given assuming it to be 238KJ/mol

we know that

ΔE= hυ

also, υ= c/λ

therefore λ = hc/ΔE

[tex]= \frac{6.626\times10^{-34}\times3\times10^8}{238\times10^3}\\=0.08352\times10^{-29} m mol[/tex]

also, 1 mol = 6.022×10^23 atoms or molecules

[tex]\lambda= 0..08352\times10^{-29}\times6.022\times10^{23}\\=502.9 \times10^{-9}m\\=502.9 nm[/tex]

Answer:

The most reactive metal elements is Group 1.

Answer:regular variation in magnitude or position around a central point. Or movement back and forth at a regular speed

Explanation:

Answer:

movement back and forth at a regular speed

Explanation:

they be oscillatin

Answer:

Ethanol.

Explanation:

Hello!

In this case, since the Fischer esterification stand for the organic acid-base reactions, we infer that the alcohol is related to the -yl part on the name (ethyl propanoate) as the alcohol is likely to lose the -OH and provide a carbocation for the carboxyl group of the carboxylic acid.

In such a way, since the -yl part is given as ethyl, we infer the used alcohol is ethanol:

[tex]CH_3-CH_2-OH[/tex]

Best regards!

Answer: When water is added to vinegar, the vinegar's acidity decreases, which results in a higher number on the pH scale. However, diluting vinegar with water can never make it alkaline, because water itself is not alkaline; the pH of the mixture can't be higher than the higher pH value of the two components.

Explanation: it loses acidity. Diluting it can never make it alkaline and the PH mixture can’t be higher.

Answer:

0.288g KBT can be dissolved

Explanation:

The dissolution of KBT produce the dissociation in K⁺ and BT⁻ ions as follows:

KBT(s) → K+(aq) + BT-(aq) Ksp = 3.8×10-4

Where Ksp is defined as:

Ksp = 3.8x10⁻⁴ = [K⁺][BT⁻]

Thus, we need to find the concentration of KBT that can be dissolved = [K⁺] = [BT⁻]:

3.8x10⁻⁴ = [K⁺][BT⁻]

3.8x10⁻⁴ = [KBT][KBT]

3.8x10⁻⁴ = [KBT]²

0.01949M = [KBT]

In 280mL = 0.280L, the moles of KBT that can be dissolved are:

0.01949mol / L * 0.280L =

5.458x10⁻³ moles of KBT. In grams (Using molar mass):

5.458x10⁻³ moles of KBT * (188.2g/mol) =

Answer:

0.0041 mol

Explanation:

Given data:

Number of formula units = 2.45 × 10²¹ formula units

Number of moles = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions ,formula units and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ formula units

2.45 × 10²¹ formula units × 1 mol / 6.022 × 10²³ formula units

0.41 × 10⁻² mol

0.0041 mol

Answer:

d = 1.91 g/cm³

d = 1.91 g/mL

Explanation:

Given data:

Mass of cheese = 67 g

Volume of cheese = 35 cm³

Density of cheese = ?

Solution:

Formula:

d = m/v

by putting values,

d = 67 g/ 35 cm³

d = 1.91 g/cm³

1cm³ = 1mL

d = 1.91 g/mL

Answer:

ΔH = -29.78 KJ/mol

Explanation:

To calculate the Standard enthalpy of change for this reaction, we need to use the following expression:

ΔH = ΔHf(products) - ΔHf(reactants)   (1)

Now, the standard heat of formation can be found in different handbooks or websites. I manage to find these for the compounds of the reaction:

ΔHf Ca(OH)₂ = -1002.82 KJ/mol

ΔHf HCl = -167.4 KJ/mol

ΔHf CaCl₂ = -795.8 KJ/mol

ΔHf  H₂O = -285.8 KJ/mol

With these values, we can calculate the enthalpy change of the reaction using (1). Let's calculate first the individual values of the products and reactants and then, we can use (1):

Reaction: Ca(OH)₂ + 2HCl ---------> CaCl₂ + 2H₂O

ΔHf (products) = ΔHf CaCl₂ + ΔHf H₂O

ΔHf (products) = (-795.8) + 2(-285.8)

ΔHf (products) = -1367.4 KJ/mol

Keep in mind that if the compound has a coefficient that balances the reaction, you need to multiply that number by the standard heat. Let's calculate reactants:

ΔHf (reactants) = ΔHf Ca(OH)₂ + ΔHf HCl

ΔHf (reactants) = (-1002.82) + 2(-167.4)

ΔHf (reactants) = -1337.62 KJ/mol

Finally using expression (1) we have:

ΔH = (-1367.4) - (-1337.22)

Answer:

X¹/⁴ Y¹/²

Explanation:

From the question given above, we are required to simplify:

⁸√(X²Y⁴)

The above expression can be simplified as follow:

⁸√(X²Y⁴)

Recall:

ⁿ√Aᵐ = Aᵐ/ⁿ

Therefore,

⁸√(X²Y⁴) = X²/⁸ Y⁴/⁸

⁸√(X²Y⁴) = X¹/⁴ Y¹/²

Thus, ⁸√(X²Y⁴) is equivalent to X¹/⁴ Y¹/²