Answer:
D
Explanation:
Melting of ice is a physical change as there no new compound is forming only state is changing So Option D is correct option. For second question Option D is correct option as combustion reaction is taking place.
What is chemical change?Chemical change is a reaction in which breaking and forming of new bonds take place. One molecule completely converted to totally different molecule. The number of atoms remains same
One famous example of chemical change is the rusting of iron. The color, odor and arrangements of atoms in products are very much different from reactant. Chemical change are mostly irreversible in nature. Physical change is just opposite of chemical change. Phase change is an example of physical change.
Thus option D is correct option in both cases.
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Which body system is similar to the nucleus?
Answer:
the brain
Explanation:
When 3.00 grams of methane, CH,, reacts according to the balanced equation below, how many molecules of water are produced?
CH, + 202 - CO2 + 2H20
Answer:
2.41×10²³ molecules of water
Explanation:
Given data:
Mass of methane = 3 g
Molecules of water formed = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of methane:
Number of moles = mass/ molar mass
Number of moles = 3 g/ 16 g/mol
Number of moles = 0.2 mol
Now we will compare the moles of water with methane.
CH₄ : 2H₂O
1 : 2
0.2 : 2 × 0.2 = 0.4 mol
Molecules of water:
1 mole = 6.022×10²³ molecules of water
0.4 mol ×6.022×10²³ molecules of water / 1mol
2.41×10²³ molecules of water
How many protons are there in a neutral, stable Hydrogen atom that makes up 99.985% of the element?
A. 1
B.2
C.3
D.4
E.0
Friendship is delicate as a glass, once broken it can be fixed but there will always be cracks. Two persons cannot long be friends if they cannot forgive each other's little failings. We all lose friends.. we lose them in death, to distance, and over time.
Answer:
make a new friend if you lose one, Its part of life losing people thats what make us people grow and be more mature.
The explosions that take place during a fireworks show are an example of which of the following? (2 points)
Image of fireworks exploding in air
Chemical change
Chemical property
Physical change
Physical property
Answer:
Chemical Change
Explanation:
The explosion of fireworks is an example of chemical change. During a chemical change, substances are changed into different substances. In another words, the composition of the substance changes.
Which of the following models best demonstrates the law of conservation of mass??
(LOOK AT THE PICTURES)!!
Answer:
i think its D
Explanation:
The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed.
Taking into account the law of conservation of mass,
The Law of Conservation of Matter is also called the law of conservation of mass or the Law of Lomonósov-Lavoisier. This law postulates that "The mass is not created or destroyed, only transformed."
This means that the reagents interact with each other and form new products with different physical and chemical properties than those of the reagents. And this is because the atoms of the substances are ordered differently.
But the quantities of the masses involved in a given reaction must be constant throughout it, that is, they will not have changed in their proportions when the reaction ends. Then the mass before the chemical reaction is equal to the mass after the reaction.
The exception to the rule is nuclear reactions, in which it is possible to convert mass into energy and vice versa.
Finally, the correct answer is option A. because the atoms of the substances are ordered differently, this is the reagents interact with each other and form new products.
Learn more about law of conservation of mass:
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will mark brainliest!!! <3
Answer:
it is C
Explanation:
I saw from Google. Hope it helps.
I cant get the full picture
sorry
Sodium has______ Valence electrons and bismuth has ________ electrons
Please help ASAP on market as brainlister
Answer:
Sodium has 1 valence electron and bismuth has 83 electrons (5 valence electrons)
Explanation:
Can y’all look at this and help please
Answer:
2, 3, 4, 5
Explanation:
Pretty sure protons matter a lot unless in acid and bases but ignore this. Atoms mostly empty space as electrons are reeeeeeeeeeaaaallllllyyyy far apart. number of electrons change it is an ion and neutrons change pretty sure its an isotope. Electrons are stupidly small and fast so they don't really count towards the weight. Most mas comes from neutrons and protons in the nucleus
Answer:
2,3,4,5
1st is wrong cuz if u change the number of proton it would change the atomic number which results in different element
6th is wrong because most mass of the atoms come from neutrons and protons collectively so if it would have said THE ATOMS MASS MOSLTY COMES FROM NUCLEONS then u could mark it right
Help meh, please !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
volume of 200mL, density shows it weighs .789 grams for every mL. .789*200= 157.8 grams
Explanation:
Infer Why is a mechanism needed to remove carbon
dioxide gas from your cells?
Answer:
Because too much Carbon Dioxide can kill us.
Explanation:
Nuclear energy is currently used in which three kinds of vehicles?
Answer:
A. cars, submarines, spacecraft
Explanation:
I took the test.
Which particle changes to create a positive or negative ion of an atom?
A.proton
B. neutron
C. electron
Answer:
it is alkali
Explanation:
hope it helps you
In the human body, a series of chemical reactions results in the making of energy that is used at both the cellular and organismal levels.
In which course would a person most likely study these chemical reactions?
biochemistry
geochemistry
materials chemistry
physical chemistry
Answer:
It is A: biochemistry
Explanation: i seen there was no answer so i took a chance and surprisingly got it correct
Answer:
e correct option is all of the above
Explanation:
write the molecular fotmula of water
Answer:
H20
Explanation:
Answer:
hope it helped you
Explanation:
H2O (u have to write ✍️no 2 below H.
You can separate air into two different substances by density. What is air?
O A. A mixture
OB. A compound
C. An atom
D. An element
SUB
Any one know the answer?
[tex]1 \: mol MgSO4 \: has \: 4 \: oxygens[/tex]
Thus ;
[tex]2 \: mols \: of \: should \: have \: 8 \: oxygens[/tex]
So the correct answer is (( 8 مول ))
How long does one complete orbit of Earth around
the sun take, give the amount in years and days?
Answer:365 days, 5 hours, 59 minutes and 16 seconds.
Which statement is not
true?
A. Protons are positive and neutrons are
neutral
B. Electrons have the most mass of the
subatomic particles
C. Protons and Neutrons are found in the
nucleus
Electrons are found outside the nucleus
and have a negative charge
Answer:
B. Electrons have the most mass of the
subatomic particles
Compared to the mass of neutron and proton, mass of electron is negligible.
Answer:
B
Explanation:
when creating a Bohr model, you will usually mark protons + or P and neutrons are usually 0 or N.
Electrons are on the rings surrounding the nucleus, but everything else is inside.
Electrons are typically represented by - or E
A mixture that is uniformly mixed is called __. a homogeneous b heterogeneous c suspension d colloid
Answer:
a. homogenous
Answer: A. homogeneous
Explanation: A mixture that is uniformly mixed is called homogeneous.
Plz mark brainliest:)
Perform the following metric conversions: Please explain bc I really dont get it at ALL !!!!
200.7 pm = _________________________nm
0.000357 hm = ______________________cm
14.78 mg = __________________________ g
8.280 μg = __________________________pg
Answer:
0.2007 nm
3.57 cm
0.01478 g
8280000 pg
Explanation:
1)200.7 pm
1 picometer is equal to 0.001 nanometer.
1 nm = 1000 pm
200.7 pm× 1 nm / 1000 pm = 0.2007 nm
2)0.000357 hm
1 hectometer is equal to 10,000 centimeter.
1 hc = 10,000 cm
0.000357 hc× 10,000 cm / 1 hc = 3.57 cm
3) 14.78 mg
1 gram is equal to 1000 milligram.
1 g = 1000 mg
14.78 mg × 1 g/1000 mg = 0.01478 g
4)8.280 µg
1 microgram is equal to 10⁶ picogram.
1 µg = 1000000 pg
8.280 µg× 10⁶ pg/ 1µg = 8.280×10⁶ pg or 8280000 pg
name the gas formed when metals react with dilute hcl
Answer:
im maybe 80% sure it's hydrogen gas
Answer:
When a metal reacts with dilute hydrochloric acid, it forms a metal chloride salt and hydrogen gas.
15
The correct formula for a compound formed from the elements Al and O is
a. AIO.
b. Al2O.
c. Al3O2-
d. AIO3.
e. Al2O3.
what is octane number
Answer:A measure of performance of fuel for internal combustion engines. Stated simply, a higher octane rating corresponds to more engine power and less knocking or other pre-ignition problems.
Explanation:
I'm also in chemistry.
Answer:
Explanation:
figure indicating the antiknock properties of a fuel, based on a comparison with a mixture of isooctane and heptane.
How can you tell if an element is a metal or a nonmetal??
Answer:
Elements to the left of the line are considered metals. Elements just to the right of the line exhibit properties of both metals and nonmetals and are termed metalloids or semimetals. Elements to the far right of the periodic table are nonmetals. The exception is hydrogen (H), the first element on the periodic table.
Explanation:
Answer:
looking at its metallic luster
Explanation:
Elements may be classified as either metals or nonmetals based on their properties. Much of the time, you can tell an element is a metal simply by looking at its metallic luster, but this isn't the only distinction between these two general groups of elements. Most elements are metals.
Selena is learning about how engineers choose metals for spacecraft. She discovers that spacecraft engineers often mix other metals with titanium. Titanium is a metal that is both lightweight and strong. It also resists corrosion. Selena wants to compare titanium with other metals. She looks at the cell from the periodic table that represents titanium.
Explain what each of the four items in the cell represents. Then, classify titanium as an alkali, alkali earth, or transition metal.
Ti is a transition metal.
Further explanationChemical symbol represent element or compound
The elements are arranged in the periodic system
1. 22This is the atomic number of Titanium
The Atomic Number (Z) indicates the number of protons of an element
2. TiThis is the symbol (chemical formula) of titanium
3. 47.90This is the mass number of Titanium
Mass Number (A) = Number of protons + Number of Neutrons
Atomic Number (Z) = Mass Number (A) - Number of Neutrons
4. TitaniumThis is the name of the element
To determine which group, alkaline, alkaline earth or transition it can be seen from the electron configuration
alkali and alkali earth : configuration from orbital 1s-7s
transition : configuration from orbital 3d-6d (Block d)
Electron configuration from Ti : [Ar] 3d²4s²
if we look at the configuration, then Ti is in the d block which is included in the transition metal
Answer:
The answer is 26
Explanation:
I just took the test
I WILL GIVE U BRAINLIEST!!!!!!!
Answer:
I think its b. if not sorry but its the one that makes most sense
Explanation:
Answer:
B
Explanation:
Hope this helps you have a nice day!
two disadvantages of series connection?
Answer:
1- if one component in a series circuit fails, then all the components in the circuit fail because the circuit has been broken.
2- the more components there are in a series circuit, the greater the circuit's resistance
What group of organic compounds include starch?
a Carbohydrates
b Lipids
Thing
C Proteins
d Nucleic Acids
An ice cube is placed in a glass of water. Which of the following best explains the
heat transfer?
A: The thermal
is moving
from the water to from the ice cube into the water into the water
causing the
temperature of
the water to
increase.
B: the thermal energy is moving from the water to the ice cube causing the temperature of the water to decrease
C: the thermal energy is moving from the ice cube into the water causing the temperature of the water to increase
D: the thermal energy is moving from the ice cube into the water causing the temperature of the water to decrease.
D: the thermal energy is moving from the ice cube into the water causing the temperature of the water to decrease.