Answer:
The properties of a pure substance can be used to determine whether a sample is a pure substance or mixture because the characteristic properties of matter can be used to identify a sample. The result is a mixture called a composite.
Explanation:
Pure substances contains their own molecules only and not any impurity. Thus, when we tested it only shows the properties of its own.
What are pure substances?Pure substances are substances containing its pure composition without any impurities. For example water, fruits, acids etc. are pure substances and they does not have a combination other substances.
Mixtures are the combination of two or more pure substances, and the can be heterogenous or homogenous. Whereas, pure substances homogenous only thus forming only one phase.
When we tested mixtures qualitatively, they shows the properties of each individual components in it. Whereas, pure substances give inly its own characteristics.
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19)
Why are unique atomic spectra produced by different elements?
changing the number of _______ makes an atom stable or unstable and creates different isotopes of the same element with a different ______ (pick two that best fits.)
a.) atomic mass
b.) atomic number
c.) protons
d.)neutrons
e.)electrons
f.) ion
g.)neutral
The neutrons are the neutral sub-atomic particles present in the nucleus. The variation in the number of neutrons produces isotopes that have different atomic mass. Thus, options 1. d and 2. a are correct.
What is an isotope?An isotope is said to be an atom of an element that have a different atomic mass but the same atomic number due to the variation in the neutrons in the nucleus. The neutrons have a neutral charge that makes the atom stable.
When a neutron is added or lost it makes the nucleus of the atom unstable leading to radioactive decay. The isotopes have the same constant number of protons in their nucleus.
The atomic number of the atom remains the same due to the stable proton number but varies the atomic mass due to the change in the number of neutrons.
Therefore, options d and a. neutrons and atomic mass are the correct blanks.
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Can someone please explain to me what a Ecologist does for a living? (Or daily in their career?)
ecologists look at relationships between nature, studying the interactions between humans, animal and plants.
Answer:
Ecologists focus on the relationship of organisms within their environment. Ecology is a branch of biology (biology is the study of life). Given the broad scope of ecology, there are multiple sub-disciplines that an ecologist can choose to focus on. Since all living things (plants, animals, microbes) depend on other living things and a healthy environment to survive, ecologists may specialize in one aspect of an ecosystem. Examples include terrestrial (land), aquatic (water), applied (concepts and principles of ecology), conversation (management of biodiversity), and evolutionary (evolution).
Explanation:
Brainliest plz
The bouncing of a wave off an object is called a what
Answer:
Reflection-energy waves bouncing off the surface of an object
Explanation:
How can you prove that air is a matter ?
Answer:
One way to prove that air is made of matter is to blow up a balloon. Before you add air into the balloon, it is empty and shapeless. When you puff air into it, the balloon expands, so you know it is filled with something—air is taking up space. You'll also notice that a balloon filled with air sinks to the ground.
Explanation:
ANSWER ASAP GIVING BRAINLIEST FIVE STARS AND A HEART!!!
Write a paragraph that explains the differences among incandescent, fluorescent, and laser light.
Answer:
An incandescent light bulb works by heating a filament in the bulb. Fluorescent light is a bright light produced by electricity flowing through a tube filled with ionized gas. Fluorescent light bulbs are more energy-efficient than incandescent bulbs.
Explanation:
How many grams of carbon is needed to react with hydrogen gas to produce 59.8 grams of acetylene (C2H2)?
Answer:
[tex]55.1657[/tex] grams/mol of carbon is needed to react with hydrogen gas to produce 59.8 grams of acetylene (C2H2)
Explanation:
The molecular weight of acetylene is 26.04 g/mol
Molecular weight of carbon is equal to 12.011 g/mol
Two carbon atom produces one acetylene molecule.
Thus, 2 * 12.011 g/mol of carbon is used to produce 26.04 g/mol of acetylene,
Amount of carbon required to produce 59.8 grams of acetylene
[tex]\frac{2*12.011}{26.04} * 59.8 \\= 55.1657[/tex]grams/mol
[tex]55.1657[/tex] grams/mol of carbon is needed to react with hydrogen gas to produce 59.8 grams of acetylene (C2H2)
Ummm help? From start to finish
Q1.
How many peaks are there in the 13C NMR spectrum of 1,4-dimethylbenzene?
A: 8
B: 4
C: 3
D: 2
Answer:
there are four peaks in the 13c NMR (B)
To solve this we must be knowing each and every concept related to NMR. Therefore, the correct option is option B among all the given options.
What is NMR?NMR spectroscopy is a form of spectroscopy that may be used to evaluate the quality or purity of such a sample as well as the molecular weight of a substance.
It really is based on the observation that now the nuclei among most atoms have spin and that all nucleus are electrically charged. NMR spectroscopy relies on the electromagnetic radiation absorption in the radiofrequency range 3kHz-300 GHz. There are four peaks in the 13C NMR spectrum of 1,4-dimethylbenzene.
It occurs at such a wavelength that corresponds to radio frequencies, and when an electron recovers from such an excited state back ground state, it produces the same frequency radio wave.
Therefore, the correct option is option B.
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Which of the following statements are true of groups on the periodic table?
Check all that apply.
A. Elements in a group have the same number of protons.
B. Elements in a group have the same number of electron shells.
C. Elements in a group have similar properties.
D. Elements in a group have the same number of neutrons.
Answer: it’s only c
Explanation:
The correct statement regarding groups on the periodic table is statement C which is elements in a group have similar properties.
A. Elements in a group may have different numbers of protons, as the group represents elements with similar valence electron configurations, but the number of protons in the nucleus can vary.
B. Elements in a group do not have the same number of electron shells. Elements within the same group have similar outer electron configurations, which determine their chemical properties. The number of electron shells increases as you go down the group.
C. Elements in a group have similar properties. Elements within the same group share similar chemical behavior due to their similar outer electron configurations. This similarity leads to recurring patterns in their physical and chemical properties.
D. Elements in a group may have different numbers of neutrons. The number of neutrons can vary within a group as different isotopes of an element can exist, which have the same number of protons but different numbers of neutrons.
Therefore, the correct option is option c
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the speed of sounds depend on
Answer:
medium in which it is traveling
Explanation:
i hope it helps u
Name the element which has twice the number of electrons in its second shell as in the first shell write it's electronic configuration also.
100 POINTS PLS HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
i need this im struggling with my work
Explanation:
Last one and the first
1. How many moles does 24 g of Mg contain?
Explanation:
1 mole Of atom = GAM
MG=24g
GAM of Mg=24g
Therefore 24g=mole
Not My answer But I saw That You needed it.
Credit zeeshanfazil
thank him for the answer!
BRAINLIST!!
Which of the following describes a process of weathering?
A.
Rocks along the coast are broken up by waves crashing into the shore.
B.
Glaciers carry boulders from mountaintops to low-lying plains.
C.
Mud, silt, sand, and pebbles are carried across the region by running water.
D.
The wind lays down sediment to form small hills called dunes.
Answer:
D or C.
Explanation:
Sorry if its wrong
Answer:
A. Rocks along the coast are broken up by waves crashing into the shore.
Explanation:
Practice Problem #2: How many atoms
of Ba are in 7.8 moles of Ba?
[tex]7.8 \: mol = \frac{6.02 \times {10}^{23} atoms}{1 \: mol} = 4.6956 \times {10}^{24} \: atoms[/tex]
round as you wish.
How many mL of a 1.00 M HCl solution would need to be added to 100 mL of 0.263 M ammonia to produce a buffer with a pH of 10.00. The pKa of ammonia is 9.25.
Answer:
3.97mL of 1.00M HCl must be added
Explanation:
The buffer of ammonia and ammonium ion follows the equation:
pH = pKa + log [NH₃] / [NH₄⁺] (1)
Where pH is the pH we want to obtain: 10.00
pKa is the pKa of the buffer: 9.25
[NH₃] could be taken as moles of ammonia
And NH₄⁺ moles of ammonium ion
When NH₃ reacts with HCl:
NH₃ + HCl → NH₄⁺ + Cl⁻
NH₄⁺ is produced. That means moles of ammonia are Initial moles of ammonia - Moles of HCl added
Moles of HCl added = Moles of ammonium ion
The total moles of the buffer are:
0.100L * (0.263mol / L) = 0.0263moles = [NH₄⁺] + [NH₃] (2)
Rewriting (1):
10.00 = 9.25 + log [NH₃] / [NH₄⁺]
0.75 = log [NH₃] / [NH₄⁺]
Replacing (2) in (1):
0.75 = log 0.0263 - [NH₄⁺] / [NH₄⁺]
5.6234 = 0.0263 - [NH₄⁺] / [NH₄⁺]
5.6234[NH₄⁺] = 0.0263 - [NH₄⁺]
6.6234[NH₄⁺] = 0.0263
[NH₄⁺] = 0.00397 moles = Moles HCl
To obtain these moles we must add:
0.00397 moles HCl * (1L / mol) = 0.00397L =
3.97mL of 1.00M HCl must be added
please help me! (brainliest)
Answer:
It is A
Explanation:
How is wind energy more environmental friendly than heat energy?
Answer:
Wind is an emissions-free source of energy
Overall, using wind to produce energy has fewer effects on the environment than many other energy sources. Wind turbines do not release emissions that can pollute the air or water (with rare exceptions), and they do not require water for cooling.
Explanation:
Most of the mass of an atom is found in
Answer:
Most of the mass of an atom is found in the nucleus.
Explanation:
Which change will cause gravitational force between and a soccer ball to increase?
Answer:
Moving the balls closer together. The distance decreases and force increases.
5. Predict which element would have a higher electron affinity: silicon or arsenic. Support your prediction with an explanation.
Answer:
Silicone
Explanation:
According to periodic trends, electron affinity increases as you go right and decreases as you go down. Silicone is above arsenic so I would expect it to have a higher electron affinity.
17.The column that an element is located in tells us
a.the total number of valence electrons an atom has.
b.the total number of energy levels an atom of that element has.
c.the highest energy level an atom of that element has.
d.both b & c.
Ha hatdog hatdog hatdog because?
Answer:
what's this? s*it fellow
uska dil ker raha tha isleye
Look at the image below:
Mid ocean ridge
Sea towe
Marie Sedie
Osta 7m
WORM
PC
hohe materieur
Tron
Orope
thenosphere
perduta
What type of plate boundary is shown here?
convergent
divergent
transform
Answer:
Divergent
20 words
Answer:
divergent...........................
4. How is a lead storage battery recharged?
a. It is heated up.
b. The pressure on it is increased.
c. A direct current is applied to it.
d. A magnet is held close to it.
Hey I'm Chloe,
Does anyone know How many sides and Octagon has?
I Tried Researching it but Nothing came up.
Look at the image below:
Mid ocean ridge
Sea Level
Celing Tin
Marine Sediment
Oceanhatsak/bero) 57 kr
pug
NOOP
thospheremantle Plazburite)
0 Ops
FR00130 kn
asthenosphere mantie
peridotite)
What type of plate boundary is shown here?
convergent
divergent
transform
Answer:
divergent is when plates move apart from each other
Answer:
thats also divergent
you sent the same picture twice
Guys pleaseeeee help:
- Which element is a member of the alkaline earth metals and has 12 neutrons?
- A burnt piece of toast is covered in this element. It is the fourth most abundant element and makes up many living things.
- Which element is an inert gas found in group VIII that produces a red glow in lights?
Answer:
Carbon- A burnt piece of toast is covered in this element. It is the fourth most abundant element and makes up many living things.
Magnesium- Which element is a member of the alkaline earth metals and has 12 neutrons?
Neon- Which element is an inert gas found in group VIII that produces a red glow in lights?
calculate 28.1g of silicon to moles
Answer:
2.53•10^23 atoms
Explanation:
23 is the exponent btw
