Answer:
yes eating the food involves both physical and chemical changes. The chewing of food is a physical change, while the mixing of saliva with food triggers chemical reactions
Explanation:
Once the food mixes with the saliva in our mouth, chemical reactions start taking place in the food, leading to its breakdown and changes in its chemical composition. An evidence of the chemical changes is the taste that we feel when we eat something sweet or sour etc.
Answer:
a chechimal
Explanation:
what makes one of your cells you ?
how different are the duck leeches offsprings from their parents
What group is not assigned electron affinities on the periodic table?
Answer:
Explanation:
halogen group
Electron affinities are negative numbers because energy is released. The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinitie
Answer:
tbh i liked how u ghosted me
Explanation:
How long does it take for 87.5 % of each isotope(Krypton-73, Krypton-74, Krypton-76, and Krypton-81) to decay?
How much radium-226 will remain from a 20 gram sample after 4800 years?
Answer:
2.5 g mass of Ra-226 will remain after 4800 years.
Explanation:
Given data:
Mass of Ra-226 = 20 g
Sample remain after 4800 years = ?
Solution:
Half life of Ra-226 = 1600 years
Number of half lives passed = T elapsed / half life
Number of half lives passed = 4800 year / 1600 year
Number of half lives passed = 3
At time zero = 20 g
At first half life = 20 g/2 = 10 g
At 2nd half life = 10 g/2 = 5 g
At 3rd half life = 5 g/2 = 2.5 g
Thus, 2.5 g mass of Ra-226 will remain after 4800 years.
Which has a higher frequency: microwaves or blue light? How do you know?
Answer:
Microwaves
Explanation:
Microwaves have more energy than blue light
Among microwaves or blue light, blue light has a higher frequency. This is because blue light belongs to the visible region has a short wavelength and produces a higher amount of energy.
What is the relationship between frequency and wavelength?The frequency of any wave is inversely related to the wavelength. This means that when the frequency of the wave increases, the wavelength decreases. While the relationship between frequency is directly related to the energy.
According to the context of this question, gamma rays have the highest frequency and shorter wavelength, while radiowaves have a shorter frequency and the highest wavelength.
Therefore, blue light has a higher frequency. This is because blue light belongs to the visible region has a short wavelength and produces a higher amount of energy.
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What is the mass of 2.25 mol of the element Iron (Fe)?
Choose the correct set up from the given choices.
a. You would divided 2.25 mol by (55.84 mol divided by 1 gram)
b. You would multiply 2.25 mol by (1mol divided by 55.84 g)
c. You would multiply 2.25 mol by (55.84g divided by 1 mol)
d. You would divide 2.25 mol by (1 mol divided by 55.84g)
Mole measure the number of elementary entities of a given substance that are present in a given sample. To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol). Therefore option c is correct option.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance.
Mathematically,
Mole of Fe element= mass of Fe element÷ Molar mass of Fe element
mass= Mole of Fe element ×Molar mass of Fe element
Substituting the given values in above formula we get
mass= 2.25 mol× 55.84 g/mole
mass= 2.25 mol× 55.84 g/mole
To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol).
Therefore option c is correct option.
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uses of indicators in points?
Answer:
The common application of indicators is the detection of end points of titrations. The colour of an indicator alters when the acidity or the oxidizing strength of the solution, or the concentration of a certain chemical species, reaches a critical range of values.
what hypothesis is best for chemical reaction?
will give Brainliest
Answer:
If the reactants in the chemical reactions are known, then the products can be predicted because the pattern of the chemical reactions is being followed. The pattern for a single replacement is A + BC --> AC + B. This is like the Hear It Pop Chemical Reaction which is also an example of the single replacement.
Explanation:
How would you define what the conductivity of a substance is?
Answer:
Conductivity of a substance is defined as 'the ability or power to conduct or transmit heat, electricity, or sound'.
Explanation:
hope it helps
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Why is it important to pasteurize certain liquids?
Answer:
Pasteurization involves heating liquids at high temperatures for short amounts of time, it can make it better if you wanted hot cocoa but bad for milk
Explanation:
Answer:
Pasteurization kills harmful microbes in milk without affecting the taste or nutritional value
Explanation:
ill attach a picture
Answer:
35.50
Explanation:
There are two stable isotopes, 35Cl (75.77%) and 37Cl (24.23%), giving chlorine a standard atomic weight of 35.45
About ______ impact the creators have been recognized on earth.
A) one thousand
B) 50
C)500
D)150
7. Base your answer to the following question on the information below and on your knowledge of biology A student designed an experiment to investigate a claim that athletes would have lower heart rates than nonathletes during exercise. After the students classified themselves as an athlete or a nonathlete, their resting pulses were determined. Then all the students performed the same exercise for four minutes and their heart rates were determined by recording the pulse rate in beats per minute. The students continued to measure their pulse rates for an additional four minutes. The average heart rate per minute for each group was determined. The data were recorded, as shown on the table below Average Heart Rate Response to Exercise (beats per minute) Time (minutes) Athlete Students Nonathlete Students Resting Pulse 68 72 1 76 78 2 82 90 Exercising Period 3 115 95 110 4 130 5 100 125 6 95 120 After Exercise 7 85 100 8 68 95 2.4 To improve the validity of the conclusion reached in this experiment, the students should repeat the experiment A) disregarding any data that don't fit the hypothesis B) with a larger number of athletes and nonathletes C) comparing the heart rates and breathing rates of males and females D) with the athletes doing different exercises than the nonathletes
What is the difference between chlorine -35 and chlorine -37?
Answer:
Free chlorine involves the amount of chlorine that's able to sanitize contaminants, while combined chlorine refers to chlorine that has combined directly with the contaminants. Total chlorine is basically the sum of free chlorine and combined chlorine.
Explanation:
chlorine -35 being chlorine
chlorine -37 being free chlorine
HELPP ASAP
What do the colors on the periodic table show?
A. which element it is
B. the metallic properties of the element
C. the types of compounds the element can make
D. whether the element is a solid, a liquid, or a gas at room temperature
Answer:
Periodic tables can use color to identify other element characteristics. For example, an electronegativity periodic table color codes the elements based on how electronegative they are. The valence periodic table uses color to identify the most common valence state for each element.Oct 2, 2019
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The color given to a the elements in periodic table is to characteristics of the elements mainly to identify whether they are solid, gas or liquid. Thus option D is correct.
What is periodic table?A periodic table contains all the discovered elements which are classified into different groups and periods. Groups are vertical columns of elements with similar properties and same number of valence electrons.
Periods are horizontal rows from left to right with an increase in atomic number. There are 18 groups and 7 periods in periodic table. Each group has given each color and some elements showing exceptional characteristics such as hydrogen and helium have separate colors.
All the first group elements called alkali metals have one color and the second groups elements with another color, All the d-block elements are given the same colour and metals in p-block elements have the same color.
Similarly, all the metalloids have one color and all other gases have the same colour in which inert gas group and halogen group have seperate colours.
Hence, the color in periodic table helps to identify the element's nature like its state also. Thus option D is correct.
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In the Bronsted-Lowry model of acids and bases, an _____ is a hydrogen donor and a _____ is a hydrogen acceptor.
Answer:
According to Bronsted-lowry concept an acid is a hydrogen donnor and a base is a hydrogen acceptor.
Explanation:
How many moles in 435 liters of Krypton gas at STP?
19.4 mol Kr
General Formulas and Concepts:Chemistry
Stoichiometry
Using Dimensional AnalysisGas Laws
STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KMath
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right Explanation:Step 1: Define
435 L Kr at STP
Step 2: Identify Conversions
[STP] 22.4 L = 1 mol
Step 3: Convert
[tex]435 \ L \ Kr(\frac{1 \ mol \ Kr}{22.4 \ L \ Kr} )[/tex] = 19.4196 mol Kr
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
19.4196 mol Kr ≈ 19.4 mol Kr
Help pls!
How can you use a chemical reaction to remove a contaminant from a solution?
Answer:
reverse osmosis
Explanation:
Water treatment is often complicated because it deals with the chemical makeup of the water, which varies widely. The first step is to determine what contaminants should be removed. Unfortunately, this is not always a straightforward process. Many contaminants make themselves known in obvious ways, such as iron or hydrogen sulfide, which can cause taste and odor issues. Other contaminants, such as arsenic or pesticides, are only uncovered through a sophisticated laboratory analysis.
It is important to test the water so that the right type of treatment system can be selected. Keep in mind, however, that more than one analysis may be necessary to get a baseline because water quality fluctuates. More information on possible contaminants in a specific area can be obtained by talking to residents, the local health department, the water department, or the state geological society. In addition, your laboratory should be able to recommend appropriate tests based on a customer’s concerns and the information provided about the water source. It is important not only to address customers’ concerns but also to educate them about potential contaminants they may not have considered.
Typhoons are large storms that form over the Pacific Ocean Hurricanes are large storms that form over the Atlantic Ocean. Which of the following are essential components in the formation of a hurricane
or a lyphoon
A High pressure, high temperature, cyclonic winds, dry air
B. High pressure cool temperature, strong winds, humid air
cWarm front, clouds, low pressure, high slevation
D Low pressure, warm temperature, warm ocean waters, spiraling winds
Please help me !!!!
Answer:
1) clouds 2) quick 3) near 4) levels 5)nucleus 6) two 7) eight 8) eighteen 9) pairs 10) properties
Explanation:
hope i helped!
Answer:
1. clouds
2. quick
3. near
4. levels
5. nucleus
6. two
7. eight
8. eighteen
9. pairs
10. properties
I do not know if I got 6-8 correctly but I got the other answersFormula for the compound that contains Mg2+ and O2-
Answer:
MgO.
Explanation:
charges of both satisfy one another (balanced) -- producing a compound MgO.
The transfer of energy in the form of invisible waves is
Answer:
Radiation
Explanation:
What do the elements in group 18 have in common?
Answer: They are all odorless, colorless, monatomic gases with very low chemical reactivity.
Explanation: Plz give brainliest
The central atom in PbSO4 is..............???????
Answer:
The central atom is S.
Explanation:
Look at the structure.
1. How many moles of Mg are there in 9.20 x 1024 atoms of Mg?
Answer:
15.28 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{9.20 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 15.282392..[/tex]
We have the final answer as
15.28 molesHope this helps you
When force are ____ the object does not move
when forces are balanced the object does not move.
Explanation:
if you and your friend push both sides of the chair at the same time with the same amount of strength the chair wouldn't move.
How many rings/energy levels would the Bohe model for an element
have if it had 12 electrons?
PLEASE HELP
The percentage by volume of oxygen in clean and dry air is approximately
Answer:
[tex]\huge\bf\underline{\underline{\pink{A}\orange{N}\red{S}\green{W}\purple{E}\blue{R}}}[/tex]
ONLY 20.95% IN THE AIR
:)
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What conclusion can she make from her experiment?
Heather is testing a substance as to whether it is
organic or inorganic. She works with the solid
substance and discovers it can conduct electricity
without burning. She also knows the carbon to oxygen
ratio is 1 to 2
O The substance is organic because it is solid at room
temperature.
O The substance is organic because it cannot burn
readily
O The substance is inorganic because it has carbon.
The substance is inorganic because it conducts
electricity
Answer:
Im pretty sure the answer is D
Explanation
Answer:
Answer D
Explanation: