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Gwar [14]
3 years ago
5

How are the sizes of stars measured? I just need a simple answer

Chemistry
1 answer:
S_A_V [24]3 years ago
7 0
They are determined by the length of time it takes for light to travel from the Earth to the desired star
You might be interested in
What do the elements within a "period" have in common? (pick one)
Gnesinka [82]

Answer:

All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.

Explanation:

6 0
3 years ago
Read 2 more answers
Write an equation for the reaction of the Tollens reagent<br> withheptanal?
dangina [55]

Answer:

CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+  3 H_2 O = CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 COOH +2Ag + 4NH_3

Explanation:

Tollens test is carried out to perceive difference between aldehydes and ketones on the basis of their capability to oxidized easily.

when Tollens react with aldehyde (heptanal) , a silver mirror is form on inner side of container.

The reaction between tollens and heptanal is given as

CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+ 3 H_2 O = CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 COOH +2Ag + 4NH_3

8 0
4 years ago
The following reaction shows sodium carbonate reacting with calcium hydroxide.
velikii [3]

Ans: 15.1 grams

Given reaction:

Na2CO3 + Ca(OH)2 → 2NaOH + CaCO3

Mass of Na2CO3 = 20.0 g

Molar mass of Na2CO3 = 105.985 g/mol

# moles of Na2CO3 = 20/105.985 = 0.1887 moles

Based on the reaction stoichiometry: 1 mole of Na2CO3 produces 2 moles of NaOH

# moles of NaOH produced = 0.1887*2 = 0.3774 moles

Molar mass of NaOH = 22.989 + 15.999 + 1.008 = 39.996 g/mol

Mass of NaOH produced = 0.3774*39.996 = 15.09 grams


5 0
3 years ago
EMPIRICAL FORMULASSSS
azamat

Answer:

34.73% of oxygen

aluminum =ALCL3

8 0
3 years ago
Please help me! <br> Which statement does not correctly describe the model of HCl?
s2008m [1.1K]

<u>Answer: </u>The correct answer is Option A.

<u>Explanation:</u>

The molecule given in the question is HCl which forms a polar covalent bond.

A polar bond is defined as the bond present between two elements with different electronegativity value. The element which has higher electronegativity value, attracts the shared pair of electrons towards itself and forms a dipole. A polar molecule is dissolved more in a polar substance than in non-polar substance.

In the given compound, the electronegativity of chlorine is more than hydrogen and attracts the shared pair of electron more towards itself and hence is a polar molecule.

A non-polar bond is defined as the bond which is formed between the elements having same electronegativity value. No dipole is created in these type of bonds. Here, the electrons are shared equally.

From the above information, the correct answer is Option A.

5 0
3 years ago
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