Echinoderms contain internal skeletons similar to the kind that vertebrates have. This internal skeleton is made up of calcium carbonate. They are marine animals. Some species of the echinoderm phylum include starfish, sea cucumbers and sea urchins.
Answer:
The atom's energy will decrease by 8.99 x 10⁻²⁶ J.
Explanation:
The atom's energy will go down by an amount equal to the energy of the photon that it emits.
The energy E of a photon is inversely proportional to its wavelength according to the following equation, where h is Planck's constant and c is the speed of light:
E = (hc)/λ
We substitute the values into the equation to solve for the energy:
E = (hc)/λ = (6.626 x 10⁻³⁴ J·s)(2.998 x 10⁸ m·s⁻¹) / 2.21 m
E = 8.99 x 10 ⁻²⁶ J
Thus, the atom's energy will decrease by 8.99 x 10⁻²⁶ J.
Answer:
2Al + 6HCl -> 2AlCl3 + 3H2
Explanation:
The experiments 'The Iced Tea Debate' and 'The Salty Soup' illustrate different physical changes and energy transfers in the context of the Law of Conservation of Matter and Energy.
In 'The Iced Tea Debate', the independent variable could be the temperature of the tea, the dependent variable could be how quickly the ice melts and the control variable could be the amount of tea used in each trial. The Law of Conservation of Matter and Energy states that matter and energy cannot be created or destroyed in an isolated system. In this case, the ice melting is a physical change, and the energy transferred is thermal energy from the tea to the ice.
In 'The Salty Soup,' the independent variable could be the amount of salt added, the dependent variable could be the taste of the soup, and the control variable could be the type of soup used. The added salt dissolving into the soup is a physical change, and no noticeable energy transfer occurs.
One example of conservation of matter and energy in everyday life is the process of photosynthesis in plants. The plant absorbs sunlight (energy), carbon dioxide, and water, and converts them into glucose and oxygen, thus conserving matter and energy.
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In these demonstrations, matter and energy were conserved, as total mass and energy stayed constant. Significant phase and energy transformations were observed, like the melting of ice and the dissolving of salt. The total mass before and after the transformations remained the same, demonstrating the law of conservation of mass.
Matter and energy can be described as being conserved in a variety of systems because they can neither be created nor destroyed, only transferred between objects or converted from one form to another. In 'The Iced Tea Debate' and 'The Salty Soup' demonstrations,
Variables would include: Independent variable: the substance added (be it ice tea or salt); Dependent variable: physical and chemical changes observed; Control variables: the initial conditions of the system, like temperature and pressure.
When analyzing the results of each of these demonstrations, you should observe energy transfers, in the form of heat in both scenarios.
Moreover, there would be conservation of matter observable in both scenarios. This can be proven by extracting and weighing all substances before and after their reactions, summing up the total mass, which should stay constant.
To answer the questions:
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Answer : The correct option is 2.
Explanation :
Number of protons = 7
Number of neutrons = 6
Number of electrons = 10
Protons are those which carries positive charge.
Electrons are those which carries negative charge.
Neutrons are those which do not carry any charge that means neutrons are neutral.
The net charge on an ion = Number of protons present in an ion + Number of electrons present in an ion
The net charge on an ion = (+7) + (-10) = -3
Therefore, the net charge on an ion is (-3).
b. using pure water
c. blowing on the hot water
d. putting the powder and hot water in a mixer
A , i think because pure water won't dissolve the powder fast.