What is the density of an object having a mass of 5.0 g and a volume of 45.0 cm3?
Answers
Answer : The density of the object will be,
Explanation :
Density : It is defined as the mass contained per unit volume.
Formula used for density :
Given :
Mass of an object = 5.0 grams
Volume =
Now put all the given values in the above formula, we get the density of an object.
Therefore, the density of the object will be,
d = 5.0 / 45.0
d = 0.111 g/cm³
Related Questions
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Which is the correct expression for Keq when the chemical reaction is as follows:N2 + 3H2 2NH3.
How many moles is 1.50 x 1023 molecules of NH3
Mrs. Rushing has 3 chemistry classes with 24 students in each. An experiment calls for each student to use 4 test tubes. How many test tubes are needed in all for her classes?A.) 32 test tubesB.) 96 test tubesC.) 288 test tubesD.) 384 test tubes
(3) unstable nuclei emit alpha particles
(4) unstable nuclei emit beta particles
Answers
The unstable nuclei emit beta particles.
What is unstable nuclei?
An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom's nucleus may result from an excess of either neutrons or protons.
What is beta particle?
- An unstable nucleus can emit a fast-moving electron called a beta particle, to become more stable.
- Beta radiation is made up of a stream of beta particles emitted from unstable nuclei.
- Beta radiation is normally emitted from unstable nuclei in which the number of neutrons is much larger than the number of protons.
- A beta particle has a relative mass that can be considered to be zero, so its mass number is zero, and as the beta particle is an electron, it can be written as ⁰₋₁e. It can also be written as ⁰₋₁β.
Atoms of I-131 spontaneously decay when the unstable nuclei emit beta particles.
The unstable nuclei undergo spontaneous decay by emitting radiations to attain stability. Stability of isotopes is based on the ratio of neutrons and protons in its nucleus. Although most nuclei are stable, some are unstable and spontaneously decay, emitting radiation.
Hence, option 4 is the answer.
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Answer;
(4) unstable nuclei emit beta particles
Atoms of I-131 spontaneously decay when the unstable nuclei emit beta particles.
Explanation;
-Unstable nuclides undergo spontaneous change or the spontaneous decay by emitting radiations to attain stability. Stability of isotopes is based on the ratio of neutrons and protons in its nucleus. Although most nuclei are stable, some areunstable and spontaneously decay, emitting radiation.
Answers
Answer:
The answer to your question is photon. An isotope remains unchanged by the emission of a gamma ray, which is a (an) photon123. A photon is a particle of light or electromagnetic radiation that has no mass and no electric charge4. A gamma ray is a type of photon that has the highest energy and frequency in the electromagnetic spectrum4. Gamma rays are emitted by the nuclei of some radioactive atoms when they undergo a nuclear rearrangement or decay4. Gamma ray emission causes no change in the number of particles in the nucleus, meaning both the atomic number and mass number remain the same23. Therefore, an isotope does not change its identity or mass when it emits a gamma ray, but only releases some excess energy as a photon. I hope this answer helps you understand the concept of gamma ray emission better.
Answers
Explanation:
It is known that one mole of chromium or molar mass of chromium is 51.99 g/mol.
It is given that number of moles is 11.9 moles.
Therefore, calculate the mass of chromium in grams as follows.
No. of moles =
mass in grams = No. of moles × Molar mass
= 11.9 moles × 51.99 g/mol
= 618.68 g
Thus, we can conclude that there are 618.68 g in 11.9 moles of chromium.
1mole ----- 52g Cr
11,9moles --- x
x = 11,9*52/1 = 618,8[g]
(1) 539°C (3) 7°C(2) –539°C (4) –7°C
Answers
The freezing point of bromine is –7°C. Therefore, the correct option is option D among all the given options.
What is bromine?
Bromine (Br) is a chemical substance, a deep red toxic liquid, and a member of Group 17 (Group VII) of both the periodic chart. At room temperature, free bromine seems to be a reddish brown fluid with such a significant vapour pressure.
Bromine vapour has an amber color. Bromine has a strong odor and can irritate the skin, eyes, especially respiratory system. Even brief exposure to intense bromine vapour can be lethal. The freezing point of bromine is –7°C.
Therefore, the correct option is option D.
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Hope this helps~
Answers
Answers
Considering the definition of electronic configuration and valence shell, the number of core electrons is 1, because the valance shell is the third energy level.
The Electronic Configuration of the elements is the arrangement of all electrons of an element in energy levels and sub-levels (orbitals).
There are 7 energy levels, numbered from 1 to 7, and in which electrons are distributed, logically in order according to their energy level. Electrons with less energy will be spinning at level 1.
Each level is divided into sub-levels. These sub-levels into which each level is divided can be up to 4. These 4 sub-levels are called: s, p, d, f.
Aufbau's principle is a principle of atomic physics, which explains how electrons are accommodated in their orbits around the nucleus of the atom.
This principle states that the filling of these orbitals occurs in increasing order of energy, that is, from the orbitals of lower energy to those of higher energy.
The simplest of the sub-levels is 1s. If you fill the 1s you can start filling the 2s. After the 2s sub-level is satisfied, the 2p can begin to fill and so on.
The valence shell is the one where the outermost electrons are found, those electrons that are in the last level. Because it is the outermost shell, it is also the farthest from the atomic nucleus.
The valence shell is one whose electrons are responsible for the chemical properties of an element.
In this case, an atom has 2 electrons in the first energy level, 8 electrons in the second energy level, and 1 electron in the third energy level. So, the number of core electrons is 1, because the valance shell is the third energy level.
Learn more:
- brainly.com/question/25653224
- brainly.com/question/19710066?referrer=searchResults
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- brainly.com/question/8140611?referrer=searchResults
- brainly.com/question/21267620?referrer=searchResults
- brainly.com/question/8001694?referrer=searchResults
Final answer:
The atom described has 10 core electrons. These are located in the first and second energy levels, which are filled from lowest to highest. The electron in the third energy level is a valence electron.
Explanation:
The question you asked involves understanding the structure of atomic energy levels (or shells). In an atom, electrons fill in the energy levels from lowest to highest. The core electrons are those in the inner energy levels.
In your case, the atom has 2 electrons in the first energy level and 8 in the second energy level, making a total of 10 core electrons. The one electron in the third energy level would be considered a valence electron, not a core electron, because it's located in the outermost energy level of the atom.
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