Answer:
C
Explanation:
This is because you are guessing that since Mrs. Sparks always carries around books, she must be a great reader. All the other answers are just facts that you see. For c, you are guessing this.
Answer:
C
Explanation:
Must is the key word. An inference is a guess, you guess Ms. Sparks must be a great reader because she is always carrying around books. You don't know for sure she is a great reader which makes it an inference. Hope this helps!
(Na2O / MgO / Al2O3 / p2O5 / So2 )
physical state :
Appearance:
Solubility:
Color:
Acidic or Basic nature :
Answer:
Na²O (Sodium-oxide)
Explanation:
Physical state - Solid
Appearance - White solid
Solubility - Yes. Formes NaOH
Color - White
Nature - Basic
The yogurt bacteria are usually Gram-positive, which means the Gram staining process dyes them ________.
Practice
A
blue
B
green
C
purple
D
pink
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.
How could you separate mixtures
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.
if the automatic number of an element is 6 and it's mass number is 14 how many neutrons are contained in the nucleus
Answer:
8
Explanation:
because 14-6 is 8
What is the weight of 7.9 ml of a solution that has a density of 1.1 g/mL?
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
What type of rock is calcite?
А) igneous
В) sedimentary
C) metamorphic
D) It's not a rock.
Calcite comes from limestones and limestones are sedimentary.
So calcate is sedimentary rock
whats the factor you observe or measure during an experiment
Answer:
Dependent variable
The molar mass of nitrogen (N2) is 28.02 g/mol. What is the mass, in grams, of 4.60 mol of Nz?
0.164
6.09
23.4
129
Answer: 129
Explanation:Please see attachment for explanation
Which of the following describes something an engineer would probably do
first when developing new technology meant to reduce ocean pollution?
O
A. Research new scientific findings in regard to ocean cleanup.
O
B. Identify the need to reduce ocean pollution.
D
C. Research what has been done in the past to clean up oceanic oil
residue.
D. Evaluate the benefits and challenges of using certain chemicals to
purify water
SUBMIT
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.
f(x) = 2x - 5
g(x) = 3x2 + 2
Find (f ·g)(x)
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.
Explanation: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.
Learn more about Functions Multiplication here:
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The number _cause of death in people between the ages of 16 and 24 is
alcohol-related driving accidents.
Otwo
three
four
one
Answer: most is 3
Explanation:
Which of the following set of pictures includes only molecules?
A piper delivers 9.98 g of water at 19 degrees Celsius. What does the pipet deliver
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]
In fossil comparisons, it helps to know about similar:
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.
is nitrogen a compound, mixture or element
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
Which of the following is equal to 1 meter?
Answer:
What following????
Explanation:
Answer:
Can you be more specific
Explanation:
A scientist read about an experiment done by someone else. She does the same experiment in her lab to make sure it works.
This is an example of
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.
What is replication of an 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.
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HgC2H6
How many molecules are contained in a 5.10-g sample of dimethylmercury?
What is the percentage of mercury (by mass) in the sample?
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.
How many moles of water are represented in a breaker containing 45.9g H2O
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.
When explaining chemical reactions to a friend, Brianna models a reaction by taking several colors of modeling clay and making a sculpture of a horse. Which type of chemical reaction is Brianna most likely explaining?
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:
If a 30 kg child were running at a rate of 9.9 m/s, what is his KE?
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.
All atoms that can enter into chemical reactions do so to either share, gain or lose electrons to achieve a stable state.
True
False
Answer:true
Explanation:
Which statements accurately describe atoms? Check all that apply.
Atoms cannot be divided.
There are only a few different types of atoms.
A single atom can be seen using a standard microscope.
Atoms were named in the fifth century BCE.
Atoms are the smallest unit of matter.
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.
how do laboratory tools improve the observations made by a scientist?
Answer:
Explanation:
Tools, instruments, apparatus are very key to research works carried out in the laboratory. The more sophisticated they become, the more efficiency they provide in making ground breaking researches.
Over the years, technological advancement has afforded scientists with new way of achieving precision and accuracy in their procedures by developing cutting edge facitlities. These equipment can help carry out better experiment and make observations simple and easy to do.
Explanation:
laboratory tools improve the observations made by a scientist in the following ways:
Primarily by improving the accuracy and precision.laboratory tools improve the efficiency of the experiment or observation made by a scientist.laboratory tools help by decreasing time and giving more prominent reproducibility of outcomes.Laboratory tools enhance the research and it makes the things easier to distinguish. laboratory tools has make more accessible the work of scientist on their research.laboratory tools help the scientist to examine their experiments for example when they want to analyze specimen, they use microscope.
What is the answer to number 14 ?
Answer:
a) 2 significant figures
b) 5 significant figures
c) 5 significant figures
d) 1 significant figures
Explanation:
• All non-zero digits are significant.
E.g. - 421 has 3 significant figures.
• Zeros between non-zero digits are significant.
E.g. - 502 has 3 significant figures.
• In a decimal less than 1, all zeros to the left of non-zero digits are not significant.
E.g. - 0.0345 has 3 significant figures.
identify each of the following as element, compound, homogenious mixture or heterogenios mixture.
a. milk
b. iron nail
c. glass
d. sugar
e. bottled spring water
f. distilled water
g. air
h. alloy bicycle frame
i. propane
j. baking soda
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.
Explanation: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
Removing Whiteboard marker residue off of books??? (Chemicals or daily products)
Answer:
Try a magic eraser!
Explanation:
Answer:
All you have to do is put a little rubbing alcohol on a rag or paper towel, rub it over the dried marks, and the Expo marker comes right off. It works on boards, books, and most other Expo marked surfaces (like refrigerators, windows, laminate countertops, etc).
8. When a 2.5 mol of sugar (C12H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. If 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? Show all calculations leading to your answer OR use 3 – 4 sentences to explain your answer.
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
. Which substance is the limiting reactant when 2 g of S reacts with 3 g of O2 and 4 g of NaOH according to the following chemical equation: 2 S (s) + 3 O2 (g) + 4 NaOH (aq) → 2 Na2SO4 (aq) + 2 H2O (l) a) S (s) b) O2 (g) c) NaOH (aq) d) none of these substances is the limiting reactant.
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.
To dilute a HCl solution from 0.400 M to 0.100 M the final volume must be
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 .