Answer:
Explanation:
Sn + 2HBr = SnBr₂ + H₂
Here HBr is an acid but Sn is not a base . It is a metal . So it is not an acid - base reaction .
HCl + KOH = KCl + H₂O
HCl is an acid and KOH is a base so it is an acid base reaction.
2AlCl₃ + 3Ca(OH)₂ = 2Al(OH)₃ + 3CaCl₂
It is an acid base reaction . It is so because aluminium hydroxide is a lewis acid and calcium hydroxide is a base . So it is an acid base reaction .
2C₂H₆ +7O₂ = 4CO₂ + 6H₂O
It is not an acid base reaction . It is actually an example of oxidation reaction in which ethane burns in oxygen to give carbon dioxide and water.
Which physical property can be measured? color density odor shape
The physical property that can be measured is the density. Color, odor and shape are properties that cannot be measured. They can be only observed through the naked eye and is subject to qualitative measurement.
Answer:
b) I took the test
Explanation:
b. changes to pressure
c. changes to precipitation
d. all of the above
Which of the following is not released by trees into the atmosphere?
a. oxygen
b. water vapor
c. ozone
d. none of the above
1. Answer is d. all of the above.
Climate can be defined as the data collection of weather conditions of a long period of time in a certain area. The weather conditions that affect to the climate are temperature, precipitation, atmospheric pressure, wind and so on. Any changes in weather can change the global climate.
2. Answer is c. ozone.
Trees release oxygen and water vapor into the atmosphere but not ozone. The oxygen gas is released by trees as the by-product of photosynthesis. This is the natural way of production of oxygen gas. Water vapor can be released due to the transpiration of trees.
1. The correct answer is option D. all of the above.
Global climate change will bring changes in temperature such as heat waves, droughts, volcanic eruption, deforestation, extinction of species due to large shift in temperatures, changes in precipitation such as heavy snowfall, ocean acidification, and ozone depletion.
2. The correct answer is option C, ozone.
Ozone is not released by trees into the atmosphere. Plants have chlorophyll and in the presence of sunlight plants uses sunlight and carbon dioxide to form glucose and oxygen.
6CO₂ + 6H₂O -> C₆H₁₂O₆ + 6O₂
During transpiration plants exhale water vapor through the stomata, tiny pores that are found on the surface of the leaves.
Thus trees never release ozone into the atmosphere.
3. Two factors that determine whether a molecule is polar are the types of atoms in the molecule and the ____________________ of the molecule.
4. According to John Dalton’s observations, when elements combine in a compound
A. The ratio of their masses is always the same.
B. Each element contributes an equal number of atoms.
C. Their volumes are always equal.
D. Their masses are always equal.
5. Democritus thought that matter was made of tiny particles
A. Of earth, air, fire, and water.
B. That could not be divided.
C. That could be divided.
D. That were all round and smooth
6. Rutherford’s gold foil experiment provided evidence for which of the following statements?
A. Negative and positive charges are spread evenly throughout an atom.
B. Alpha particles have a positive charge.
C. Gold is not as dense as previously thought.
D. There is a dense, positively charged mass in the center of an atom.
7. Which statement about subatomic particles is true?
A. Protons, neutrons, and electrons all have about the same mass.
B. Unlike protons or neutrons, electrons have no mass.
C. Neutrons have no charge and no mass.
D. An electron has far less mass than either a proton or neutron.
8. Which statement is true about oxygen-17 and oxygen-18?
A. They do not have the same number of protons.
B. Their atoms have an identical mass.
C. They are isotopes of oxygen.
D. They have the same mass number.
9. Which statement accurately represents the arrangement of electrons in Bohr’s atomic model?
A. Electrons vibrate in fixed locations around the nucleus.
B. Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.
C. Electrons travel around the nucleus in fixed energy levels with equal amounts of energy.
D. Electrons travel randomly in the relatively large space outside the nucleus.
10. What does the electron cloud model describe?
A. The most likely locations of electrons in atoms
B. The precise locations of electrons in atoms
C. The number of electrons in an atom
D. The mass of the electrons in an atom
11. What is the difference between an atom in the ground state and an atom in an excited state?
A. The atom in the ground state has less energy and is less stable than the atom in an excited state.
B. The atom in an excited state has one fewer electron than the atom in the ground state.
C. The atom in an excited state has more energy and is less stable than the atom in the ground state.
D. The atom in an excited state has one more electron than the atom in the ground state.
12. The usefulness of Mendeleev’s periodic table was confirmed by
A. the discovery of subatomic particles.
B. its immediate acceptance by other scientists.
C. the discovery of elements with predicted properties.
D. the discovery of the nucleus.
13. Atoms of the most reactive elements tend to have
A. one or seven valence electrons.
B. eight valence electrons.
C. four or five valence electrons.
D. no valence electrons.
This answer explains chemical concepts related to the periodic table, atomic theory, the nature of molecules, and properties of subatomic particles.
1. Mendeleev organized elements in his periodic table in order of increasing atomic mass.
2. You would select the compound with the highest melting point as the ionic compound.
3. The types of atoms in the molecule and the shape of the molecule determine whether a molecule is polar.
4. According to Dalton, The ratio of their masses is always the same when elements combine in a compound.
5. Democritus thought that matter was made of tiny particles that could not be divided.
6. Rutherford’s gold foil experiment provided evidence that there is a dense, positively charged mass in the center of an atom.
7. It’s true that an electron has far less mass than either a proton or neutron.
8. Oxygen-17 and oxygen-18 are isotopes of oxygen.
9. In Bohr’s atomic model, electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.
10. The electron cloud model describes the most likely locations of electrons.
11. An atom in an excited state has more energy, and is less stable than an atom in the ground state.
12. The usefulness of Mendeleev’s periodic table was confirmed by the discovery of elements with predicted properties.
13. Atoms of the most reactive elements tend to have one or seven valence electrons.
#SPJ11
A) fusion
B) fission
C) radiance
D) solar flaring
Answer: Option (A) is the correct answer.
Explanation:
The process in which two or more small nuclei combine together to result in the formation of a larger nuclei is known as fusion.
In Sun, four hydrogen nuclei combine together to result in the formation of helium atom. This combining of small hydrogen nuclei to form a large helium nuclei represents fusion process occurring inside the Sun.
Thus, we can conclude that to power itself, the sun is constantly generating a nuclear reaction in its core, in which hydrogen nuclei are combined to form helium. This process is known as fusion.
Answer: -
Without the sun, life on earth would not exist. There would be no warmth, no plants, no animals, no night and day.
To power itself, the sun is constantly generating a nuclear reaction in its core, in which hydrogen nuclei are combined to form helium. This process is known as
A) Fusion
Fusion produces a lot of energy but very little radioactive waste.
Answer:
442.7m
Explanation:
12.42m+421.0m+9.28
442.7m