Answer:
A pure substance has a definite chemical composition
A pure substance has a definite chemical composition in all states. Pure substance can be composed of multiple elements but the composition does not alter in any case.
What are pure substances ?Pure substances are formed either a single component or a combination of more components with a definite composition forming a single phase. Unlike mixtures a pure substance cannot be separated into its components physically.
For example pure water is a pure substance. Water is formed from hydrogen and oxygen atoms in a definite proportion forming a molecular compound that does not alter anyway.
However, salt solution, mixture of two gases etc. are not pure substance. They haven't a definite composition and can be separated by some physical methods. Hence, option c is correct.
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An gel ice pack getting cold after you put it in the freezer for an hour.
substance change
chemical change
elemental change
physical change
Answer:
physical change
.............
How many inner transition metals are there?
Answer: 28 inner transition elements
I need help pleases and can you explain
Answer:butterflies
Explanation:
Nah man you are on your own.
Positive oxidation number suggest the element wants to ____ (gain/lose) electron
Answer:
lose electron
Explanation:
If the oxidation number is positive, this means that the atom loss electrons.
Losing electrons makes the atom lose some of its negative charge and become more positively charged.
Hope that helps.
Why is it difficult to detect the presence of isotopes of an element during chemical
studies?
Answer:
Isotopes are atoms that have different number of neutrons, so they have a different mass number than the other atoms in an element.
Which cellular process produces simple sugars?
A. mitosis
B. photosynthesis
C. respiration
D. waste elimination
Answer:
The answer is C. Hope this helps you out!
Answer:
C. Respiration
✂---------------
The element with 8 valence electrons and 5 energy levels.
What is the volume of 8.80 g of CH4 gas at STP?
Answer:
12.32 L.
Explanation:
The following data were obtained from the question:
Mass of CH4 = 8.80 g
Volume of CH4 =?
Next, we shall determine the number of mole in 8.80 g of CH4. This can be obtained as follow:
Mass of CH4 = 8.80 g
Molar mass of CH4 = 12 + (1×4) = 12 + 4 = 16 g/mol
Mole of CH4 =?
Mole = mass/Molar mass
Mole of CH4 = 8.80 / 16
Mole of CH4 = 0.55 mole.
Finally, we shall determine the volume of the gas at stp as illustrated below:
1 mole of a gas occupies 22.4 L at stp.
Therefore, 0.55 mole of CH4 will occupy = 0.55 × 22.4 = 12.32 L.
Thus, 8.80 g of CH4 occupies 12.32 L at STP.
The energy of a pendulum is recorded at different positions in the table below. Use the data in the table to determine the amount of kinetic energy the pendulum had at Position 2.
Answer:
46.5 J
Explanation:
I did it in stemscopes.
40 g of sodium reacts with ____ g of chlorine to produce 117 g of sodium chloride *
Answer:
9.26g of chlorine
Explanation:
Can somebody plz help answer all of these questions right it’s very important. If u can that will be amazing thanks!
WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST :DDD
Answer:
1. Mechanical energy
2. Heat/thermal energy
3. Electrical energy
4. Heat energy
5. Electrical energy
Explanation:
Hope this helped!
Fields allow some objects to exert forces on each other even when they are not ________.
Answer:
in contact
Explanation:
Fields allow some objects to exert force on each other even when they are not contact with one another.
The region of space where the effect of a force is felt is know as a field.
Field forces for provides a non-contact means of exerting forces. They objects do not have to be in contact before the force is felt. An example is the gravitational force field.Fields allow some objects to exert forces on each other even when they are not in contact .
i need help please will give brainliest
Answer:
1) Least reactive 2) Halogens 3) Nonmetals
Explanation:
What would happen to a plant if you grew it in a room without cabon dioxide
Answer:
One of the byproducts of respiration is CO2, this is the opposite of photosynthesis. It is not unusual for plants to stop taking in carbon dioxide to uptake small amounts of oxygen at night. In the event that plants cease to take up CO2 all together, they will cease to convert sunlight into carbohydrates, and die.17/01/2019
Explanation:
Does this equation follow the laws of conservation of mass? why?
CuO(s) + H2(g) = Cu(s) + H2O(g)
(twos are subscript_)
Answer:
Yes
Explanation:
Chemical equation:
CuO + H₂ → Cu + H₂O
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given reaction:
CuO + H₂ → Cu + H₂O
there are 1 copper atoms, one oxygen atoms and two hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
When an object that is made of magnetic material but is not a magnet comes in contact with a magnet _____. PLS ANSWER FAST
Answer:
Magnetic domains fall into alignment and it begins to attract other objects.
2 points
2. CsH&BrCl is a compound. What is the ratio of carbon to bromine atoms
in the molecule?
O 1:1
1:3
O 1:6
3:1
3:6
61
361
Answer: The ratio of carbon to bromine atoms in the molecule is 3:1
Explanation:
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass. It can be decomposed into simpler constituents using chemical reactions.
Chemical formula shows the elements in a compound and the relative proportions of those elements.
The chemical formula given for the compound is [tex]C_3H_6BrCl[/tex] which means the ratio of carbon to bromine atoms is 3: 1.
Thus the ratio of carbon to bromine atoms in the molecule is 3:1
how did quantum mechanics change our understanding of atoms
Answer:
in quantum mechanics, electrons exist in a cloud-shaped area outside the nucleus.
Explanation:
Need Help ! ASAP !! Please
Answer:
Option 1.
Explanation:
3.6cm * 1inch/2.54 cm = 1.417 inch
How many total oxygen atoms are in 2Ba(NO3)2
Answer:
6
Explanation:
How many parts does CsF ( Cesium Fluoride ) have?
What are the signs of a chemical reaction?
A. Color change and gas released
B. Color, Gas, Explosion, Smoke,
Precipitate
C. Color, Gas, Light, Temperature, Precipitate
Answer:
C
Explanation:
Because i just had to do this on my assignment and got 100
Answer:
hey , its option c because in chemical reaction colour + evolution of gas takes place + temp. + precipitation. but also light can come in the case of chemical reaction.
Animals and humans obtain the energy they need from what?
A. food
B. water
C. carbon dioxide
D. photosynthesis
Answer:
A. Food
Explanation:
Water alone does not give energy, Carbon Dioxide cannot be consumed healthily, and photosynthesis is for plants.
The Mississippi River carries tons of tiny rock fragments called sediments into the Gulf of Mexico. What do you think will happen to these sediments after a few million years?
Answer:build up
Explanation:
Answer:
The sediments will be transformed into rock.
Explanation:
Hope this helps, Good Luck, let me know if i am wrong, and Brainliest?
Okay so I am working on polyatomic ions and need help what is the name of this element KCH3COO
Answer:
its potassium acetate
Explanation:
.............................
Can someone please help and list what each type of thing they are? (Element, Compound, Mixture of elements, Mixture of compounds, Mixture of elements and compounds)
A chemical equation can be used to solve stoichiometry problems provided that it....
indicates only the forward reaction and not the reverse.
indicates that reactants are in the gas phase and are not solids or liquids.
includes the coefficients that are needed for balancing the equation.
includes the state of matter after each substance.
Answer:
includes the coefficients that are needed for balancing the equation.
Explanation:
A chemical equation can be used to solve stoichiometry problems provided that it includes the coefficients that are needed for balancing the equation.Hence, Option (C) is Correct.
What is Balanced Equation ?
An equation that has an equal number of atoms of each element on both sides of the equation is called a balanced chemical equation, i.e., the mass of the reactants is equal to the mass of the products.
Therefore, A chemical equation can be used to solve stoichiometry problems provided that it includes the coefficients that are needed for balancing the equation.Hence, Option (C) is Correct.
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10. Write the formula for the compounds: copper (1) chloride and copper (II) chloride
Answer:
Copper(II) chloride (CuCl2) reacts with several metals to produce copper metal or copper(I) chloride (CuCl) with oxidation of the other metal.
Explanation:
There are two types of chemical compound one is covalent compound and other is ionic compound. The formula for the compounds: copper(I) chloride and copper (II) chloride are CuCl and CuCl[tex]_2[/tex] respectively.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion. Covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron.
The chemical formula for Copper(II) chloride is (CuCl[tex]_2[/tex]). The chemical formula for copper(I) chloride (CuCl). The number in the roman is the oxidation state of the metal. Copper(II) is called cupric, copper(I) is called cuprous.
Therefore, the formula for the compounds: copper(I) chloride and copper (II) chloride are CuCl and CuCl[tex]_2[/tex] respectively.
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Which of the following accurately describes a synthesis reaction?
Answer:
The 5th answer
Explanation:
This can be easily remembered by
A + B --> AB
ex:
2Na(s) + Cl2(g) --> 2NaCl(s)
Plz help hurry! I will give brainlest
Answer: mitochondria
Explanation:
it affects the cell because it produces the power of the cell, let me know if this helpes