Antonio and Addie want to know if perfume fumes affect plant height. They place five identical bean plants in five identical light boxes. In four of the boxes, they place 200 milliliters (mL) of perfume at different distances from the plants, and they make observations twice a week for one month. Which choice best identifies the observation data that should be included in their data table?

Answer:

C is the false one atoms contain chemical bonds

Answer:

C. Atoms contain chemical bonds.

Reason:

Atoms don't have any chemical bonds. Molecules are the particles have chemical bonds.

Answer:

First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)

Zn + 2HCl ==> ZnCl2 + H2(g)

moles of H2 desired:  PV = nRT

n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)

n = 0.409 mole H2 desired

moles Zn needed:

0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed

mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)

Explanation:people always get this wrong but i got you

Answer:

6.25gm

half life is 66hrs 11 days is 24*11 then take that and divide by 66 to find out how many time it will have halved and half 50 by that many times

Explanation:

If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.

Molybdenum-99 follows first-order decay.

First-order decay means that for a population of atoms (e.g. radioactive), molecules, or anything else, a constant fraction/unit time is converted to something else.

The half-life (th) of Mo-99 is 66 h.

We will find its rate constant (k) using the following expression.

k = ln2 / th = ln2 / 66 h = 0.011 h⁻¹

Next, we will convert 11 days to hours, knowing that 1 day = 24 h.

11 d × 24 h/1 d = 264 h

If we start with 50 g of Mo-99, we can calculate the remaining mass after 264 h using the following expression.

[tex][Mo] = [Mo]_0 \times e ^{-k \times t} }\\\\[Mo] = 50g \times e ^{-0.011 h^{-1} \times 264 h} } = 2.7 g[/tex]

where,

If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.

Learn more about first-order decay here: https://brainly.com/question/14478152

Answer: The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper sulphate heptahydrate.

Explanation:

Water of crystallisation is the number of water molecules that combine chemically in definite molecular proportion with the concerned salt in the crystalline state.

The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper (II) sulphate heptahydrate as there are 7 molecules of water.

Answer:

it can tell and show what pathogen is in you as well what type and mutation so then your body can fight back and remember the genetic dna so then you will be immune in some way.

Explanation:

Question;

How does a fever aid an immune response?

Answer:

One type of immune cell jumps into the fray after body temperature rises, according to experiments in mice. A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes

Answer:

S0rRy i d0nT kn0w fRenCh

Answer:

i think niether

Explanation:

Answer:

Have a wonderful day :) thanks for the points

Answer:

Cells are the smallest living unit of an organism

Answer:

all living things living things have blood cells

Explanation:

this is because robert hooke did not make this apart of the theory

Answer:

AN ELECTRON HAS THE SMALLEST MASS!

Answer:

A) electron

good luck, i hope this helps :)

Answer:

Melting and Boiling Point Determination

The physical properties of a substance can be used to establish its purity. These properties include the melting point and boiling point. Different substances tend to have different melting and boiling points, and any pure substance will have a specific melting and boiling point.

Explanation:

1. Pb(CO3)2

Element Number Mass Percet Composition

Oxygen 6 16.00 29.34%

Carbon 2 12.01 7.34%

Lead 1 207.21 63.32%

2. Ga(OH)3

Element Number Mass Percet Composition

Hydrogen 3 1.0079 2.50%

Oxygen. 3 16.00 39.75%

Gallium 1 69.72 57.74%

3. P4O10

Element Number Mass Percet Composition

Oxygen. 10 16.00. 56.36%

Phosphorus. 4 30.97 43.64%

4. Ca3P2

Element Number Mass Percet Composition

Phosphorus 2 30.97 34.00%

Calcium. 3 40.08 66.00%

5. Ti(NO3)3

Element Number Mass Percet Composition

Oxygen. 9 16.00 61.56%

Titanium. 1 47.87 20.47%

Nitrogen. 3 14.01 17.97%

Answer:

4.16 * 10²⁴ particles

Explanation:

1. We convert from grams to moles

4 g NaCl / 58 g of NaCl = 0.0689655172 moles

-> 0.0690 moles

2. Now we will convert from moles to particles by multiplying by avogadro's number..

0.0690 * 6.022 *10²³ = 4.15518 * 10²⁴ particles or 4.16 * 10²⁴ particles

Explanation:

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Answer:

Expansion: increase in size Contraction: decrease in size

Explanation:

The increase in size of an object on heating is called expansion where as the decrease in size of an object on cooling is called contraction.

Answer:

[tex]T_f=72.5\°C[/tex]

Explanation:

Hello!

In this case, since this a problem in which the cold water is heated by the hot water, we can write:

[tex]Q_{hot}+Q_{cold}=0[/tex]

Thus, by plugging in the mass, specific heat and temperatures, we obtain:

[tex]m_{hot}C_{hot}(T_f-T_{hot})+m_{cold}C_{cold}(T_f-T_{cold})=0[/tex]

Now, we can also write:

[tex]m_{hot}(T_f-T_{hot})+m_{cold}(T_f-T_{cold})=0[/tex]

Then, after applying some algebra, it is possible to obtain:

[tex]T_f=\frac{m_{hot}T_{hot}+m_{cold}T_{cold}}{m_{hot}+m_{cold}}[/tex]

If we plug in, we obtain:

[tex]T_f=\frac{350.0g*95.0\°C+150.0g*20.0\°C}{350.0g+150.0g}[/tex]

[tex]T_f=72.5\°C[/tex]

Best regards!

Answer:

1: A b/c the table is showing that each different surface resulted in different time for acceleration.

2: D b/c the if the same force is applied to two different masses, the smaller masses would be impacted more and move faster. The larger an object is, then the greater the force you will need for it to move the same distance as the smaller masses.

Answer: A. HNO3

Explanation:

Which of the following sources could not be used to obtain the DNA of a person lost in a mass disaster?

food found in the victim's refrigerator could not be used to obtain the DNA of a person lost in a mass disaster.

So, correct answer is 2nd one.

Answer:

because they react with other gases of atmosphere and pollute the environment

Answer:

C4H4

Explanation:

92.31% of 52.0 g/mol is 48.0012 g/mol

7.69% of 52.0 g/mol is is 3.9988 g/mol

Carbon has a gram-formula mass of about 12, which goes into 48.0012 about 4 times, so there should be 4 atoms of Carbon

Hydrogen has a gram-formula mass of about 1, which goes into 3.9988 about 4 times, so there should also be 4 atoms of hydrogen

Answer:

A. 2H₂O₂  → 2H₂O + O₂

Explanation:

If we make a net sum of both reactions, we're left with:

Grouping species:

There is OI⁻ at both sides, so it is eliminated -same goes for the catalyst, I⁻-.

Thus the answer is option A.