Answer:
Hey there!
A scientist would try to determine the cause of the food poisoning, and see if the people who got poisoned had anything in common, for example: they ate at the same restaurant, they are all people of a certain age, etc.
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The table describes how some substances were formed.
Substance
P.
Q
Description
Formed by boiling pure water
Formed by combining three hydrogen atoms to every nitrogen atom
Formed by adding 5 g of sugar to 1 L of water
Formed by compressing carbon under high pressure
R
S
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Explanation:
Which is a pure substance?
1. soda
2. gasoline
3. salt water
4. carbon dioxide
carbon dioxide
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of -7.2°C. Bromine can be classified as a
1. compound.
2. impure substance.
3. mixture.
4. pure substance.
pure substance.
Answer:
the answer is
Explanation:
Sugar and water make a homogeneous mixture (the same proportions of its components throughout any given sample).
The melting points of ionic compounds _____
Explanation:
ionic compounds have high melting points
Three determinations were made of the following percentage of oxygen in mercuric oxide. The results were 7.40%, 7.43%, and 7.35%. What was the average percentage?
what are the efficient things needed for a village
Answer:
Those aspects which are something a village needs are specified beneath.
Explanation:
Things being equally necessary to make living simpler and therefore more enjoyable. The government has promised to continue providing basic facilities to either an unpopulated location, including such roads, drinkable water, as well as electric power. Therefore, throughout the village, certain things accessible with maximum variety and quality that have become the basic requirements for this human existence.Which of the following is NOT the property of a non-metal? A. Non-rigid structure B. Not ductile C. Low density D. Malleable
Answer:
The answer is D.
Explanation:
Malleable is the property of metal not non-metal.
Answer:
malleable
Explanation:
because a non metal cannot be harmmed into sheetsGive two examples of neutralization
Answer:examples for neutralization - treating indigestion,treatment for insect bites.hope it help you
Explanation:
what is the correct electron configuration for an element with five electrons in the third energy level
[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.
What are elements?Elements are the simplest substances which cannot be broken down using chemical methods.
The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.
The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries 32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.
The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
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Di- Ethyl zinc is a chemical used in the library to protect books from worms, its composition is 53% Zinc, 38.9% Carbon, and 8.1% Hydrogen (At mass of Zn=65.4, C=12, H=1). Find the empirical formula of a compound
Answer:
ZnC4H10
Explanation:
The empirical formula of a compound refers to the formula that gives the simplest whole number ratio of each atoms of the elements in the compound.
The empirical formula is calculated thus:
The given percentages in the question represent the mass in grams of each element in the compound.
Zinc= 53%, C= 38.9%, H= 8.1% which represents 53g, 38.9g and 8.1g of each element respectively.
Molar Mass of Zn= 65.4 g/mol
Molar Mass of C= 12 g/mol
Molar Mass of H= 1 g/mol
Step 1: Divide the mass of each element by the molar mass given to convert to moles:
Zn= 53/65.4 = 0.81moles
C= 38.9/12 = 3.24moles
H= 8.1/1 = 8.1moles
Step 2: Divide each mole value by the smallest number of moles calculated, which is 0.81moles:
Zn= 0.81/0.81 = 1
C= 3.24/0.81 = 4
H= 8.1/0.81= 10
This is the mole ratio represented in the subscript of each element in the empirical formula:
That is, Zn (1) C (4) H (10)
Empirical formula= ZnC4H10
3. why are fire tornadoes rare ?
what’s the answer to this?
how scientific inferences can be made from scientific observations
Answer:
The scientific method is applied to inference through the steps taken to make both inductive and deductive inferences. Inductive inference begins with an observation, and then a pattern of such observation develops. One then makes a hypothesis based on the pattern and finally a theory based on the hypothesis
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All the simple machines make work easier to do by changing the _____ or _____ of a force. A. size; type B. work; type C. size; direction D. type; direction
Answer:
C. size; direction
Explanation:
By definition, a machine is referred to any device that makes work easier. It takes force to do work, hence, work refers to the application of force over a particular distance. A machine aims at making the work easy by changing how it is done. Simple machines, which include: levers, pulleys, inclined planes etc. all carry out the same thing, which is to make work easier, by changing the size/magnitude and direction of the applied force.
A simple machine tends to change the size of the inputted force by increasing it over a shorter distance. The machine increases the force applied better than it can be done manually e.g. a plier and nutcracker increases/changes the applied force better than it can be done with bare hands.
Also, a simple machine can achieve making work easier by changing the direction at which the force is applied. The machine applies the force on the object in an opposite direction or contrary to the way it was manually applied.
Explain why chlorine is a gas while iodine is a solid yet both are halogens. Select one: a. Both iodine and chlorine differ in strength of metallic bonds b. Chlorine has strong inter molecular forces than iodine c. Iodine molecules are large with strong inter molecular forces than chlorine
Answer:
Chlorine has strong inter molecular forces than iodine
Explanation:
Answer:
Chlorine has strong inter molecular forces than iodine
Explanation:
I2 is a solid while Cl2 is a gas because Iodine molecules are larger and therefore experience stronger intermolecular forces.
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What is the molarity of a 50.0ml aqueous solution containing 10.0 grams of hydrogen peroxide H2O2
Molarity= No of moles of solute * 1000 / vol solution in ml
No of moles= Given mass / Molar mass
Given Mass of solute (H2O2)= 10g
Molar mass of H2O2=34gmol^-1
No of moles= 10/34= 0.294 moles
Volume of solution=50ml
Molarity = 0.294*1000 / 50
Molarity = 5.8M
Questions
1 Explain why a solid expands when it is heated.
2 Explain how the liquid in a thermometer changes so that it can be used to
measure a temperature.
3 Use particle theory to explain why solids and liquids cannot be compressed
(squashed into a smaller volume).
4 Use particle theory to explain why liquids and gases can flow.
Answer:
answer of question 1 is
Explanation:
solids are denser than liquid and gases because solid particles are closely packed and do not have any empty spaces between their particels so when solid will heated its particles will spread and there will have more spaces between them so a solid expand on heating.
5 (01.01 LC)
Which of the following would be a warning sign that information about a weight loss medication is not reliable science?
Answer:
The scientists and all test subjects involved in the investigation work for the company that sells the medication.
Explanation:
The options are as below:
A. The investigation compared a group that took the medication to a control group that did not take the medication.
B. The scientists and all test subjects involved in the investigation work for the company that sells the medication.
C. The weight loss medication worked for 95 out of the 100 test subjects, while only 15 of the 100 control subjects lost weight.
D. The weight loss results were replicated by scientists conducting a study at an independent institution
The correct option would be that the scientists and all test subjects involved in the investigation work for the company that sells the medication.
When selecting the test subjects for research, the selection must be as random as possible so as to ensure an unbiased outcome and increase the reliability of the research.
Limiting the test subjects to those that work in the company that sells the medication will generally reduce the reliability of the outcome because of element of bias that can be introduced either knowingly or unknowingly.
The test subjects must have been selected from the general population of target users for the medication and not limited to just the employees of the manufacturing company.
Correct option: B
Sulphur dioxide is a common pollutant from burning coal.State two effects caused by this pollutant and also write the chemical equation.
Heya!
Sulfur dioxide - ( SO2 )
Answer:
Sulfur dioxide is a common pollutant caused due to the burning of coal,Is very harmful for the environment and health.Effects:
Health effects-Sulfur dioxide effects the respiratory system which includes the functioning of lungs,respiratory track and causes infections,can also effect and irritate the eyes and causes aggravating conditions such as asthma and chronic bronchitis.As most sulfur dioxide air pollution comes from the burning of coal and oil in power plants. It is a emitted by trains, large ships and other diesel objects that burns alota sulfur fuel so this also effects the environment like plants and others as the air lacks oxygen ,but with more sulfur dioxide.Hope this helps!
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Write down the dissolution equation for nickel(II) perchlorate dissolving in water. (Perchlorate is a polyatomic ion with the formula ClO41-.) If four moles of the ionic compound are dissolved, then how many moles of the ANION are present in the solution?
Answer:
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
8 mol ClO₄⁻
Explanation:
Let's consider the dissolution equation for nickel(II) perchlorate dissolving in water.
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
The molar ratio of Ni(ClO₄)₂ to ClO₄⁻ is 1:2. If 4 moles of Ni(ClO₄)₂ are dissolved, the moles of ClO₄⁻ formed are:
4 mol Ni(ClO₄)₂ × (2 mol ClO₄⁻/ 1 mol Ni(ClO₄)₂) = 8 mol ClO₄⁻
In science class, Jake mixed water with differing amounts of an unknown liquid. After mixing the liquids, he heated 20 milliliters (ml) of each mixture and observed how quickly it boiled. The table shows his results.
According to the question, each mixture decrease the boiling point of the water.
What is boiling point ?Boiling temperature is defined as the temperature at which liquid change into a vapour at the atmospheric pressure at sea or ocean level.
For example the boiling temperature of water is 100 degree celcius.
Thus, each mixture decrease the boiling point of the water, option "A" is correct.
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Which are the physical properties of water
which state of matter is Na OH(s)
Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
Perform the forlowing
mathematical operation, and
report the answer to the correct
number of significant figures.
4568/13 = [?]
Answer:
[tex]\large \boxed{350}[/tex]
Explanation:
In multiplication and division problems, the answer can have no more significant figures than the number with the fewest significant figures.
My calculator gives the result:
[tex]\dfrac{4568}{13} = 351.3846154[/tex]
4658 has four significant figures.
13 has two significant figures.
You must round to two significant figures.
That is, you drop all the digits to the right of the 5 — the red line in Fig. 1 below. You are rounding to the nearest ten.
To round a number to the nearest ten, you look at the number in the ones place (1). See Fig. 2.
If the number to be dropped — the digit in the ones place — is less than 5, you drop the digit in the ones place (Fig. 3). It becomes a zero.
The number in the tens place is a trailing zero. It is not significant.
[tex]\text{The quotient of $\dfrac{4658}{13}$ is $\large \boxed{\mathbf{350}}$}[/tex]
In the image above the ruler is measuring in centimeters. The blue cylinder falls somewhere between 2.7cm and 2.8cm according to the ruler. Since we can estimate the last digit I would say that the length of the cylinder is 2.76cm. Since I am estimating any number 2.72cm or 2.78cm could also be correct.
Why would 2.755 not be a correct measurement according to estimating the last digit?
Answer:
The answer is below
Explanation:
Resolution is the smallest unit of measurement that can be measured by a measuring instrument. Each point on the ruler is 0.1 cm and the difference between any two points, about 0.01 cm cam be measured. The minimum measurement (resolution) that can be measured by the ruler is 0.01 cm (two decimals), therefore it cannot measure up to three decimal places such as numbers like 2.755.
PLZ HELP! TIMED TEST Which of the following groups of elements are likely to have elements in the three states of matter? (1 point)
Alkali metals
Actinides
Halogens
Lanthanides
Answer:
Halogens
Explanation:
Matter is defined as a substance which has mass and occupies volume. The three states of matter are solid, liquid and gas.
Elements which are present in group 17 are known as halogens.
Elements present in this group are fluorine, chlorine, bromine and iodine.
At room temperature, both fluorine and chlorine exists as a gas.
Bromine exists as a liquid and iodine exists as a solid.
Therefore, we can conclude that halogen groups are likely to have elements in three states of matter.
What is atom economy? A. All of these B. The system that determines how much 1 mole of a pure element costs. C. The measure of how much of the reactants end up as products in a chemical reaction. D. The system of exchanging electrons that occurs in atoms.
Answer:
C
Explanation:
It's the amount of products you get compared to all the reactants you use. It's kind of like economy in that it's profit, and the higher the atom economy the more products/profit you have.
Answer:
C.) The measure of how much of the reactants end up as products in a chemical reaction.
Explanation:
I got it right on founders edtell.
Which scientist developed a new model of planetary motion?
Answer: Johannes Kepler
Answer:
i believe the answer us kepler
Explanation:
Iron and aluminum are examples of
Answer:
Iron and aluminum are both examples of metals that are used commonly in everyday life.
In the laboratory, a volume of 100 mL of sulfuric acid (H2SO4) is recorded. How many g are there of the liquid if its density is 1.83 g / cm3?
Answer:
[tex]\large \boxed{\text{183 g}}[/tex]
Explanation:
[tex]\begin{array}{rcl}\text{Density} & = & \dfrac{\text{Mass}}{\text{Volume}}\\\\\rho & = &\dfrac{m}{V}\\\\1.83 \text{ g$\cdot$ cm}^{-3} & = & \dfrac{m}{\text{100 cm}^{3}}\\\\m & = & \text{183 g}\\\end{array}\\\text{There are $\large \boxed{\textbf{183 g}}$ of sulfuric acid.}[/tex]
Define freezing....... Correct and detailed answers will be marked as Brainliest.
The transformation of liquid into solid when it reaches when it's temperature is below freezing point.
Answer:
Freezing:
When liquid is converted to solid, the process is called freezing.
Conditions for freezing:
1) Temperature must be lowered.
2) The temperature should be below 0 degree centigrade.
Example:
The conversion of "liquid water" into "ice".
=> We can use a "freezer" to freeze things.
The primary function of a scuba regulator is to: Reduce high-pressure gas in the scuba cylinder to a more breathable intermediate pressure. Reduce high-pressure gas in the scuba cylinder to ambient (surrounding) pressure. Provide a diver with a continuous flow of oxygenated air. None of the above.
Answer:
Reduce high-pressure gas in the scuba cylinder to ambient (surrounding) pressure.
Explanation:
The primary function of a scuba regulator would be to reduce high-pressure gas in the scuba cylinder to ambient pressure.
A scuba regulator is a structure found attached to the scuba cylinder usually carried by scuba divers. The structure regulates the pressure of the breathing gas in the cylinder to a safe level before the gas becomes available for the breathing process of divers.
Usually, the gas in a scuba cylinder is at a high level. Hence, what the regulator does is to bring it down to a level that would be safe for the breathing of the diver.
