Which of the following statements is true?

The scientific method is based on personal judgment.

Every Thursday Patrick eats pizza. This is a cause and effect relationship.

A false hypothesis means there is something wrong with the experiment.

Sharing an experiment with a friend is a great way to communicate results.

Answer:

Dependent variable

Answer:

The staining process will dye them purple (option C)

Explanation:

Gram staining is a method of staining used to distinguish and classify bacterial species into two large groups. Those 2 groups are called Gram- positive and gram - negative groups.

This staining is based on the composition of their cell wall. Gram staining uses crystal violet to stain cell walls, iodine as a mordant, and a fuchsin or safranin counterstain to mark all bacteria.

⇒ Gram- positive bacteria are called gram - positive because they will give a positive result. This according to their cell wand. Their cell wall is typically rich with peptidoglycan and lacks the secondary membrane and lipopolysaccharide layer found in Gram-negative bacteria

Gram- positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured.

⇒ Gram- negative bacteria are called gram - negative because they will give a negative gram result.

Because of the presence of higher lipid content, after the alcohol-treatment, the porosity of the cell wall increases, hence the CVI complex (crystal violet – iodine) can pass through. Thus, the primary stain (crystal violet) is not retained. Gram negative bacteria will appear red or pink.

Yogurt is produced using a culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus bacteria. (In addition, other lactobacilli and bifidobacteria). All of those bacteria are gram-positive, what means they will appear purple.

Answer:

These are the mixtures,compunds,Homogenious mixture,hetrogenios mixture and element:

Explanation:

a. Milk: Homogeneous mixture.

b. Iron nail: Element.

c. Glass: Compound (specifically, an amorphous solid).

d. Sugar: Compound (specifically, a carbohydrate).

e. Bottled spring water: Homogeneous mixture.

f. Distilled water: Homogeneous mixture.

g. Air: Homogeneous mixture.

h. Alloy bicycle frame: Homogeneous mixture (specifically, a solid solution)

i. Propane: Compound (specifically, an alkane hydrocarbon)..

j. Baking soda: Compound (specifically, sodium bicarbonate).

Milk is a homogeneous mixture, iron nail is an element, glass is a compound, sugar is a compound, bottled spring water is a homogeneous mixture, distilled water is a homogeneous mixture, air is a homogeneous mixture, an alloy bicycle frame is a homogeneous mixture, propane is a compound, and baking soda is a compound.

a. Milk - Homogeneous mixture

b. Iron nail - Element

c. Glass - Compound

d. Sugar - Compound

e. Bottled spring water - Homogeneous mixture

f. Distilled water - Homogeneous mixture

g. Air - Homogeneous mixture

h. Alloy bicycle frame - Homogeneous mixture

i. Propane - Compound

j. Baking soda - Compound

Answer:

The Kelvin temperature scale reflects the relationship between temperature and average kinetic energy.

Explanation:

The Kelvin temperature of a substance is directly equal to the average kinetic energy of the particles of a substance.

Answer:

Is a direct relation among them

Explanation:

As you increase the kinetic energy of the molecules, the temperature will increase, if the molecules have more energy, will move faster.

Check the graphic.

When the particles absorb some energy from the surroundings, it will start to save it, until the element do not want to be in a compound or in a certain state of matter, it will be independent

Hope this info is useful.

Answer:

In the given question Brianna is trying to make a whole figure by combining different  single elements.

Explanation:

Here are the different  coloured that are used to join and make one piece this method that Brianna is following is called synthesis.

The combination here is of simple substances that are combined directly to make a complex compound. The compound formed is complex while the substances that combined together can be element or compound  or a combination of both.

Answer: synthesis

Explanation:

Answer:

9.99 ml water will be delivered from pipet

Explanation:

When Water is being delivered by the pipet the temperature is 19 degree Celsius. Also know that dependence of density is on temperature although this temperature dependence is inverse in nature that is when temperature increases density decreases and vice versa.

Now we also know the density of water at 20 ° Is [tex]0.99 gml-1[/tex].

At this temperature 9.98 gram will occupy a volume= [tex]0.98/0.998= 9.997ml[/tex]

Answer:

S is the limiting reagent.

Explanation:

To find the limiting reactant we must first write the balanced chemical reaction. It must be correctly balanced so that we can find the proper mole ratios.

2 S (s) + 3 O2 (g) + 4 NaOH (aq) → 2 Na2SO4 (aq) + 2 H2O (l)

After this we will convert our measurements to moles. For mass we do this by dividing by the molar mass.

2g ÷ 32.06 = 0.06238mol S

3g ÷ 32.00 = 0.09375mol O₂

Now that we have the moles of each of the reactants, we can multiply them by their mole ratio with a reactant.

0.06238mol S × 2/2 = 0.06238mol H2O

0.09375mol O₂ × 2/3 = 0.06250mol H2O

S is our limiting reagent because it makes the smaller amount of moles.

Answer:

8

Explanation:

because 14-6 is 8

Answer:

The boiling point of the water by adding 2.5 moles of aluminium nitrate will be changed by 4° C.

Explanation:

Step 1: define the formula for an elevation of the boiling point

Δ T b  = i *K b *bB

⇒with Δ T b = the elevation of the boiling point ( in °C or Kelvin)

⇒with i = van't Hoff  i -factor for the solute. The factor i shows the number of individual particles (typically ions) that are formed by a compound in the solution.

⇒ with Kb = ebullioscopic constant, which depends on the properties of the solvent. (Eventually can be calculated).

⇒ with bB= the molal concentration (molality) of the solute.

Since we have 2 different solutions ( component 1 = sugar and component 2 = aluminium nitrate) of the same molality in the same solvent ( water). We can express this as followed:

Δ T b,2 / Δ T b,1  = (i2 * Kb * bB ) / (i1 * Kb *bB)

⇒after he was simplifying this becomes:

Δ T b,2 / Δ T b,1  = i2 / i1

⇒ Now we can isolate either Δ T b,2 or Δ T b,1:

Δ T b,2  =(i2/i1) x Δ T b,1

Sugar

⇒ is a covalent compound, so it doesn't dissociate in water ⇔ i1=1

Aluminium nitrate

⇒ it's a soluble ionic compound and in solution it will dissociate as the following equation:

Al(NO3)3 (aq) → Al3+(aq)  + 3NO3- (aq)

⇒thus here are 4 particels formed : 1 Al3+ + 3NO3-

i2=4

As given, we also know that the temperature was raised by 1°C after adding sugar ⇒ Δ T b,1 = 1°C

Step 2: insert all the numbers in the formula for boiling point elevation

(i2/i1) x Δ T b,1

(4/1 ) x 1°C = 4°C

⇒ The boiling point of the water by adding 2.5 moles of aluminium nitrate will be changed by 4°C

Answer: 129

Explanation:Please see attachment for explanation

Answer:

so measuring stuff is easier and simple

Explanation:

Answer:

Na²O (Sodium-oxide)

Explanation:

Physical state - Solid

Appearance - White solid

Solubility - Yes. Formes NaOH

Color - White

Nature - Basic

Answer:

Explanation:

Since mixtures are impure substances that do no combine chemically, they can be separated by physical means. Mixtures are best separated using the different separation techniques. Some of the techniques are filtration, decantation, distillation, e.t.c The separation techniques will restore different components of the mixture into their separate phases and composition.

Nitrogen, also known as "N", with a mass of 14.0067 u and the atomic number of 7, is known mostly an element (it is a chemical element) and when it is elements like this, it is in a periodic table (Fun Fact: Nitrogen is colorless and an unreactive odorless gas element.) It is an element.

Hope this helped!

Nate

Answer:

living things, fossils, and places

Explanation:

Comparing fossils involves examining similarities and differences in physical form, DNA, and proteins, as well as rock distribution and types to understand evolutionary relationships. The study of taxonomy and evolutionary patterns is enhanced by the integration of genetic data with fossil evidence.

In the context of fossil comparisons, it is critical to know about similar species both from the present and the past, as fossils highlight differences and similarities in forms, shedding light on the evolutionary process. Such comparisons often involve analyzing the anatomy, distribution, and environmental context of fossils.

A key example of this can be found when examining the Archaeopteryx fossil, which shares many features with modern birds, helping to establish evolutionary links. Not only do physical characteristics play a role, but similarities in DNA or protein sequences between species also offer insights into their evolutionary relationships, confirming patterns suggested by the fossil record.

Moreover, different rock types and their distributions, as well as rocks from ancient climate zones, provide additional context that can help determine the age and environment in which these organisms lived. When analyzing a fossil, consider the type of skeleton, its body plan (including symmetry), its likely habitat, and how it might have fed and behaved.

Such information contributes to our understanding of the organism's paleo-environment. The study of index fossils is particularly useful for correlating the age of different rock layers across geographical regions.

Understanding taxonomy and using fossils for comparative anatomy studies are classic methods for reconstructing evolutionary histories.

However, genetics has taken a front seat in comparative studies due to its direct link to the source code of life, allowing for more precise evolutionary timings via mitochondrial DNA (mtDNA) analyses in conjunction with fossil data. Extinct species comparisons to extant ones illuminate evolutionary storylines and highlight continuities and transitions across time.

Answer:

There are 2.55 moles of water.

Explanation:

First you have to calculate the molar mass fo water ⇒ 18 grs/mol.

Then 18 grs ----------- 1 mol H2O

        45.9 grs ------- 2.55 moles of H2O

There are 2.55 moles of water.

Calcite comes from limestones and limestones are sedimentary.

So calcate is sedimentary rock

Answer:

What following????

Explanation:

Answer:

Can you be more specific

Explanation:

Answer:

8.69 g

Explanation:

density = 1.1 g/mL

it means,

1 ml of the solution has a mass of 1.1 g

∴7.9 ml of the solution has a mass of =(1.1 x7.9) g

                                                              =8.69 g

Answer:

30 kg x 9.9m/s=297 N

Explanation:

When, a 30 kg child were running at a rate of 9.9 m/s, then child's kinetic energy is 1470.15 joules.

The student's question is concerned with calculating the kinetic energy (KE) of a child running at a certain speed. Kinetic energy can be calculated using the formula KE = (1/2)mv₂, where m is mass and v is velocity. In this case, since the student has provided the values of the child's mass (30 kg) and the speed (9.9 m/s), we can compute the kinetic energy.

First, square the velocity: 9.9 m/s imes 9.9 m/s = 98.01 m/s². Next, multiply this value by the mass of the child and then divide by 2 to get the final kinetic energy:

KE = (1/2)imes 30 kg imes 98.01 m2/s2 = 1470.15 J (joules).

Therefore, the kinetic energy of a 30 kg child running at 9.9 m/s is 1470.15 joules.

Answer:

g(x) = 2 always

Explanation

No matter the value, even if you write F(x), its value is always 2! SKSKSKSKS PERIOD !!!!!

The product of the two functions f(x) and g(x), represented as (f · g)(x), is found by multiplying the equations together. The resulting equation after applying distributive property is 6x^3 - 15x^2 + 4x - 10.

The question asks for the product of two functions, f(x) and g(x). This is denoted as (f · g)(x), which is the multiplication of respective function values.

The functions given are f(x) = 2x - 5 and g(x) = 3x^2 + 2. To find (f · g)(x), we multiply these two functions together.

(f · g)(x) = (2x - 5)(3x^2 + 2).

Using distributive property, the result is: 6x^3 + 4x - 15x^2 - 10

So, (f · g)(x) = 6x^3 - 15x^2 + 4x - 10 is the product of the two functions.

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Answer:

The final volume must be 400 mL.

Explanation:

Let us assume the Initial volume as 100ml

Using dilution factor formula  

[tex]\\$M_{1} \times V_{1}=M_{2} \times V_{2}$\\\\$0.400 M \times 100 m l=0.100 M \times V_{2}$[/tex]

So,

[tex]$V_{2}=\frac{0.400 M \times 100 m l}{0.100 M}=400 m l$[/tex]

Thus, the final volume must be 400 mL.

Explanation:

Molarity of HCl ,[tex]M_1= 0.400 M[/tex]

Volume of the HCl solution = [tex]V_1=500mL[/tex] (assume)

Molarity of HCl after dilution [tex]M_1= 0.100 M[/tex]

Volume of new HCl solution = [tex]V_2[/tex]

[tex]M_1V_1=M_2V_2[/tex]

[tex]0.400 M\times 500 mL=0.100 M\times V_2[/tex]

[tex]V_2=\frac{0.400 M\times 500 mL}{0.100 M}=2000 mL[/tex]

[tex]\frac{V_1}{V_2}=\frac{500 mL}{2000 mL}[/tex]

[tex]V_2=4\times V_1[/tex]

In order to dilute a HCl solution from 0.400 M to 0.100 M the final volume must be 4 times the initial volume of 0.400 M HCl solution .

Answer: most is 3

Explanation:

Answer:

It’s Replication

Explanation:

If someone conducts an experiment which is done once already at the same conditions and criterias, it can be said as replicating the experiment. Hence, this is an example of replication of the experiment.

Replication is the act of repeating an experimental setup in order to gauge the phenomenon variability. As defined by ASTM in standard E1847, replication is "the repetition of the entire set of the experimental treatment combinations to be compared. A replicate is one of the repeats."

Repeated measurements of the same item are not the same as replication since they are handled differently in statistical experimental design and data processing.

Single-item testing or evaluation may not be representative of a batch or process and does not account for item-to-item variation. Therefore, repeating the same experiment to test the productivity of the results of an experiment is called replication.

To find more on experimental replication, refer here:

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Answer:

- Atoms cannot be divided

- Atoms were named in the fifth century BCE

- Atoms are the smallest unit of matter

Explanation:

- The atom is widely known as the smallest unit matter is made of, which obtains properties of a chemical element.

- Atom can be regarded as indivisible amount of a chemical element having its own existance.

- All states of matter are made of neutral or ionized atoms.

- In the 5th century BCE, the basic concept of atom was by the atomist school in Ancient Greece.

Answer:

The number of molecules= 1.33 × 10∧22 molecules

percentage of mercury = 87%

Explanation:

Given data:

mass of dimethyl mercury = 5.10 g

number molecules of dimethyl mercury in 5.10 g = ?

percentage of mercury = ?

Solution:

First of all we will calculate the molar mass of dimethyl mercury.

molar mass of HgC2H6 = 1×200.6 + 2×12 + 6×1 = 230.6 g/mol

we know that,

230.6 g of HgC2H6 = 1 mol = 6.02 × 10∧23 molecules.

so

For the 5.10 g of sample:

5.10 g/230 g/mol = 0.022 moles of HgC2H6

now we will multiply these number of moles with Avogadro number to get number of molecules in 5.10 g of sample.

0.022 × 6.02 × 10∧23 molecules = 0.133  × 10∧23 molecules or

1.33 × 10∧22 molecules.

Percentage of mercury:

Formula:

percentage = (atomic number of Hg × total number of atoms of Hg/ molar mass of HgC2H6) × 100

% age of Hg = (200.6 g/mol× 1/ 230.6 g/mol) × 100

%age of Hg = 0.869 × 100

%age of Hg = 86.99 % or 87 %

There are approximately [tex]\(1.33 \times 10^{22}\)[/tex] molecules in the sample, and mercury constitutes approximately [tex]\(87.00\%\)[/tex] of the sample's mass.

1. Calculate the number of moles of dimethylmercury:

[tex]\[ \text{Number of moles} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{5.10 \, \text{g}}{230.658 \, \text{g/mol}} \approx 0.0221 \, \text{moles} \][/tex]

2. Calculate the number of molecules using Avogadro's number:

[tex]\[ \text{Number of molecules} = \text{Number of moles} \times N_A \approx 0.0221 \, \text{moles} \times 6.022 \times 10^{23} \, \text{molecules/mol} \approx 1.33 \times 10^{22} \, \text{molecules} \][/tex]

3. Calculate the percentage of mercury (by mass) in the sample:

[tex]\[ \text{Percentage of mercury} = \frac{\text{Molar mass of Hg}}{\text{Molar mass of HgC}_2\text{H}_6} \times 100\% \]\[ = \frac{200.59 \, \text{g/mol}}{230.658 \, \text{g/mol}} \times 100\% \approx 87.00\% \][/tex]

So, there are approximately [tex]\(1.33 \times 10^{22}\)[/tex] molecules in the sample, and mercury constitutes approximately [tex]\(87.00\%\)[/tex] of the sample's mass.

Final answer:

The initial step an engineer takes when developing technology to combat ocean pollution is to identify the pollution reduction need, consider the effectiveness of existing methods, and understand the impacts on marine life and biodiversity.

Explanation:

When an engineer is developing new technology to reduce ocean pollution, the first step they would likely take is to identify the need to reduce ocean pollution. This involves understanding the problems caused by pollutants, such as how oil spills can cover the surface of the ocean, reducing light and oxygen penetration and adversely affecting marine life. Engineers must also consider the effectiveness of current methods for dealing with pollution, such as the use of chemicals and bioremediation for oil clean-up, and the impacts of those methods on marine biodiversity and ecosystems. This foundational step frames the direction of subsequent research and design efforts aimed at creating new, effective solutions.

Answer:

Option =C each mouse in the study has brown ears.

Explanation:

Qualitative:

Qualitative properties are those that can be only observed but not measured in numerical values. These are observed through senses: touch, sight, smell, taste and hear.

For example:

Color, odor, brittleness, taste etc.

Quantitative:

Quantitative properties can be measured in numerical values.

For example:

Melting point, boiling point, conductivity, viscosity, density, hardness and solubility.

In short we can say that qualitative is a measure of quality while the quantitative is a measure of quantity.