Answer:
Classifying stars according to their spectrum is a very powerful way to begin to understand how they work. As we said last time, the spectral sequence O, B, A, F, G, K, M is a temperature sequence, with the hottest stars being of type O (surface temperatures 30,000-40,000 K), and the coolest stars being of type M (surface temperatures around 3,000 K). Because hot stars are blue, and cool stars are red, the temperature sequence is also a color sequence. It is sometimes helpful, though, to classify objects according to two different properties. Let's say we try to classify stars according to their apparent brightness, also. We could make a plot with color on one axis, and apparent brightness on the other axis, like this:
Explanation:
Hidrogen gas is a diatomic gas, this is H2, which means that one molecule of gas has two atoms (every molecule of hydrogen gas consists in H2).
The particles in gases are the molecules, not atoms.
So, every molecule is a particle, and when you are told that you have 1 mole of hygrogen gas means that you have 1 mole of H2 molecules which is the same that 1 mole of particles.
Therefore, the answer is one mole.
Answer:
10 moles of SO₂ are produced when 5 moles of FeS₂
Explanation:
Stoichiometry: it is the theoretical proportion in which the chemical species are combined in a chemical reaction. The stoichiometric equation of a chemical reaction relates molecules or number of moles of all the reagents and products that participate in the reaction.
In other words, stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships established are molar relationships (that is, moles) between the compounds or elements that make up the chemical equation.
The stoichiometric coefficients of a chemical reaction indicate the proportion in which said substances react.
Taking into account the above, you can apply the following rule of three: by stoichiometry if 4 moles of FeS₂ produce 8 moles of SO₂, then when reacting 5 moles of FeS₂ how many moles of SO₂ will they produce?

moles of SO₂= 10
<u><em>10 moles of SO₂ are produced when 5 moles of FeS₂</em></u>
The name of this alkane is with central carbons are bonded to c h 3 is 2-methylbutane.
<h3>
What is alkane?</h3>
Alkanes belong to the family of saturated hydrocarbons with carbon carbon single bond.
For the given alkane;
CH₃ H
CH₃ - C - C - CH₃
H H
Thus, the name of this alkane is with central carbons are bonded to c h 3 is 2-methylbutane.
Learn more about alkane here: brainly.com/question/24270289
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Answer:
1. the group number of sodium is 1 and it is a metal
2. the group number of helium is 18 and it is a nonmetal
3. the group number of iodine is 17 and it is a nonmetal
4.the group number of calcium is 2 and it is a metal
5. lithium has similar properties to potassium
6. calcium has similar properties to magnesium
7. neon has similar properties to xenon
8. Iodine has similar properties to chlorine