Answer:
Water boils - physical change
Salt dissolves in water- chemical change
Milk turns sour- chemical change
metal rusts - chemical change
Explanation:
A chemical change refers to changes that are irreversible and the process involves the evolution of heat along with the formation of a new substance, examples include;Salt dissolves in water, Milk turns sour, metal rusts etc
The boiling of water is a physical change. The water can be cooled and the vapour condensed,hence, the boiling of water is a physical change.
Physical changes are easily reversible and no new substance is formed.
What is 0.0000000652 in scientific notation?
Answer:
it denotes 6.52× 10⁸ in scientific notation
How do electrons of an element determine that element's reactivity?
Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
Key Concepts
Choose the letter of the best answer.
1. Which description defines pseudoscience?
A. process of investigation that resembles science and follows scientific methods
B. process of investigation that resembles science but does not follow scientific methods
C. process of investigation that does not resemble science but follows scientific methods
D. process of investigation that does not resemble science and does not follow scientific methods
Answer:
A
Explanation:
John Fang has 5 apples, Jonny ate 3, how many are left!
Describe the changes in energy that occur when a marshmallow is burned over a fire?
Answer:
When marshmallows are toasted, a chemical change occurs. The sugar molecules in the marshmallow are being changed into carbon (1). Sugar can be changed into water molecules. ... The flame on stage - oxygen diffuses to the surface of the marshmallow from the surrounding air.
Which of the following is an example of a crystalline solid?
O A. Rubber
O B. Plastic
C. Diamond
O D. Glass
Negative and positive ions alternate in the ionic crystals. For instance, the melting point of calcium fluoride (CaF[tex]_2[/tex]) is 1418 °C. Therefore, the correct option is option C.
What is Crystalline Solid?The description of crystalline solid states that it is a substance whose atoms or even subatomic particles are organized in a highly structured form. Atomic nuclei in metallic crystals are surrounded by a "sea" of delocalized electrons.
Molecules of many types make up molecular crystals. Atoms that are covalently bound to one another make up covalent network crystals. Jewelry is crafted with diamond. Quartz is used to create things like watches and wall clocks. Among all the given options diamond is the only compound which is Crystalline Solid.
Therefore, the correct option is option C.
To learn more about Crystalline Solid, here:
https://brainly.com/question/28274778
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If you find the mass of a sample to be 42.1 g and the actual mass is 42.0 g. your percent error would be what?
Answer:
0.24%
Explanation:
To find the percent error, first subtract the actual value by the expected value. You can ignore the sign of the difference.
42.0 - 42.1 = -0.1 = 0.1
Divide the difference by the expected value and multiply by 100%.
0.1/42.1 = 0.0024 × 100% = 0.24%
The percent error is 0.24%.
5.25 calories are absorbed by an iron nail. How many joules is this?
a) 1.07
b) 9.43
c) 12.6
d) 21.9
* I NEED EXPLANATION!!! *
Answer:
D) 21.9
Explanation:
1 kilocalorie is equal to 4184 joules
0.001 kilocalorie is equal to 1 calorie
so 5.25 calorie=21.966 joules
The chemical formula for glucose is C6H1206. How many different elements make up one
molecule of glucose?
Answer:
3 different elements make up Glucose
Explanation:
C = Carbon ( *6 )
H = Hydrogen ( *12 )
O = Oxygen ( *6 )
The building has 25 stories.
Qualitative or Quantitative?
Answer:
Quantitative
Explanation:
Quantitative statements involve numbers. (Ex: The house has 4 bedrooms.)Qualitative statements describe characteristics. (Ex: The house is blue.)Different organisms have different "habitats." These are all examples of habitats: The tops of banana trees in a rainforest The moist area inside a log on a forest floor The sand on the bottom of a shallow area of the ocean Which survival need best defines "habitat"? oxygen or carbon dioxide someplace to live food water
Answer:
Oxygen/Carbon dioxide
Explanation:
The basic description of living things are organisms which have a cell system to produce energy with either primarily via respiratory exchange abilities, by the existence .
The primal survival need for a possessing a habitat would have to be oxygen/carbon dioxide present,
I hope this was helpful.
Answer:
Habitat
Explanation:
Thats what its called when an animal has a home there habitat
Write each number in standard notation.
0.9x 10-1
how to Convert 2.00 miles to fathoms?
Answer:
1,760
Explanation:
There are 880 fathoms in a mile. To convert miles to fathoms, multiply the mile value by 880.
So, 2.00 × 880 = 1,760
How many calories are absorbed by a copper spoon with a mass of 200 grams as it changes from 28°C to 33°C?
a) 0.00027
b) 3
c) 90
d) 13,000
Answer:
c) 90
Explanation:
Answer:
C
Explanation:
The amount of heat required to increase temperature by Δ T of an object with mass m and specific heat s is given by Q = m s Δ T . For copper specific heat s = 0.09 c a l / go C
Which of the following is equivalent to 3.2 mg?
a
3.2 x 10-15 ug
b 3.2 x 1015 ug
С
3.2 x 10-3 ug
d
3.2 x 10'ug
Answer:
The options are not really clear, however, the answer is 3.2 × 10^3ug
Explanation:
Milligram (mg) and microgram (ug) are interconvertible measurements of mass or weight. One microgram (ug) is a millionth gram while one milligram (mg) is a thousandth gram.
Hence, one milligram is a thousandth microgram i.e. 1 mg = 1000 ug
Therefore, a measurement of 3.2mg in ug will be; 3.2 × 1000
= 3200
= 3.2 × 10^3 ug
Hence, an equivalent measurement of 3.2mg is 3.2 × 10^3ug.
Where is the most energy transferred in a food web?
a
From decomposer to secondary consumer
b
From producer to primary consumer
c
From primary consumer to secondary consumer
d
From secondary consumer to primary consumer
Explanation:
from producer to primary consumer is the correct answer of this question
Answer:
The answer is B.
Explanation:
"From producer to primary consumer"
Have a nice day, and keep dreaming <3
How many moles is 50g of CaCO3?
[tex]\huge\underline\mathbb\pink{♡Your Answer♡}[/tex]
Formula mass of CaCO3 is
40 + 12 + 3-100amu....
100g CaCO3 = 1 mole..
50g of CaCO3 = 1÷ 100x 5 = 0.5mole...
Hence ,answer is 0.5mole...[tex]<marquee direction="left" scrollamount=10><font color=purple>[/tex]
Hope it helps you..
Thanks...
What is the problem with mental models?
Mental models also guide your perception and behavior. They are the thinking tools that you use to understand life, make decisions, and solve problems. Learning a new mental model gives you a new way to see the world—like Richard Feynman learning a new math technique. Mental models are imperfect, but useful.
hope this helped :)
A teacher is preparing the materials list for an activity that all 6th graders will
complete. Each student will create a scale model of the planets in Earth's solar
system. A student will need 2,250 mg of clay to create a model of Mercury.
What two conversion factors will the teacher need to use in determining how
many kilograms of clay to order?
Answer:
There are 1000 mg in 1. g
There are 1000 g in 1 kg
Each students needs 2,250 mg of clay
Explanation:
In order to determine the amount of how many kilograms to order, the teacher will need to find out the total mass of clay required by the students and then the teacher will have to convert the total mass to the units required for the purchase.
The teacher would have to find out how many milligrams make one kilogram as follows
1 kg = 1000 g
1 g = 1000 mg
Therefore, 2,250 mg = 2250/1000 g = 2.25 g
2.25 g = 2.25/1000 kg = 0.00225 kg.
What is the density of a 234 g sample with a volume of 22 mL?
Answer: 10.63
Explanation: You divide the mass by volume.
Answer:
10.64g/cm³
Explanation:
1cm³ = 1ml
22 × 1cm³ = 22cm³
Density = Mass ÷ Volume
234 ÷ 22
Density = 10.64g/cm³ or 10640kg/m³
3. In all cells, genetic materials are stored in the
A. Cell wall
B. Ribosomes
C. Nucleus
D. Lysosomes
Which of these statements contains an inference? Question 10 options: After three substances were mixed with a blue liquid, the well plate got warmer. No chemical reaction occured in well #5. Upon mixing, the liquids had a milky appearance. The substance was heated and a clear liquid formed.
Answer:
None
Explanation:
In reporting experimental procedures/analyses, the inference is made after multiple observations have been summed up, to find the nearest possible outcome that explains the phenomenon.
If all options are listed in the question, nothing was inferred after the procedure and observation.
An example of inference would be "CO23- present" or "Chloride formation"
I hope this explanation is clear.
what do they all have the same of ?
Answer:
Same # of protons.
Explanation:
It's right cuz I took the test like last year and I still remember the answer
why is nuclear fision relevant?
Answer:
nuclear vision provides energy for nuclear power and drives the explosion of nuclear weapons both uses are possible because certain substances called nuclear fuels undergo visions when struck by fishing neutrons and turned into emit neutrons when they break apart
Explanation:
I remember taking this test and seen this on the test and it was correct
define a primary source and secondary source
Answer:
primary source: documents the result of original researche.
: is written by those who have conducted researche.
: includes firsthand information about their methodologies, data, results or conclusions.
Secondary source: summarizes, compares, critiques or interprets the primary source.
Explanation:
Primary source is the research articles published in scholarly, peer reviewed journal.
Secondary source is the summarises, critiques or interpretations of primary source.
If the mass of an object stays the same but its volume decreases, will the density increase or decrease?
Answer:
Increase
Explanation:
Density = Mass ÷ Volume
Let the mass be 100 for instance and the original volume to be 4.
100 ÷ 4 = 25
The new volume let it be 2.
100 ÷ 2 = 50
50 is more than 25 so the density increases
The expression “like a ton of bricks” means “very hard.” Would being hit by an actual ton of bricks hurt if it happened on the moon? A. Yes, it would hurt because the bricks would still have the same weight B. No, it would not hurt as much because the bricks would have less weight C. Yes, it would hurt because the bricks would still have the same mass D. No, it would not hurt as much because the bricks would have less mass.
Answer:
The correct option is;
C. Yes, it would hurt because the bricks would still have the same mass
Explanation:
Given that the expression "like a ton of brick" refers to the tendency of an object being crushed by another object, which is due to the impact of the force, and from Newton's law a force is proportional to the rate of change of momentum produced, therefor if the brick of the same mass is given the same velocity as it had on the Earth while the person remains stationary, it will hurt if the brick hits the person.
i need famous invention from the last 200 years
Answer:
ancient Egyptian event lighthouses including the huge lighthouse of Alexandria
Explanation:
-250 BCE
Describe how the Buchner funnel was used to filter the ocean water. What went through the
filter?
Answer:
ya um i though i know it
Explanation:
An organic chemistry student is experimentally determining the melting point of fluorenone. The experimental melting points are listed below from a to e. Which one should he discard so that he can say his data is precise?a. 83.5 °C.
b. 85.6 °C.
c. 83.6 °C.
d. 83.4 °C.
e. 83.3 °C.
Answer:
To say his data is precise, he has to discard option b - 85.6 degrees Celsius
Explanation:
During laboratory experiments, the precision of a result data covers the sameness of the data generated or results got each time the experiment is performed.
For the results to be seen as precise, the temperatures recorded during each experiment should be the same, or really close to each other.
Judging based on that, option B does not fit in as it is quite different from the other results by about 2 degrees Celsius. It also indicates that some errors may have occurred during the experiment.
To say his data is precise, he has to discard option b - 85.6 degrees Celsius.
The other temperatures recorded are close to each other. This would now make the data precise.