Why do lighthouses use lenses?

Answers

Answer 1

Answer: To see far away? I'm thinking that like human glasses, lighthouses need lenses to see the far away boats. Or humans.

Related Questions

Consider the reaction C12H22O11(s)+12O2(g)→12CO2(g)+11H2O(l) in which 10.0 g of sucrose, C12H22O11, was burned in a bomb calorimeter with a heat capacity of 7.50 kJ/∘C. The temperature increase inside the calorimeter was found to be 22.0 ∘C. Calculate the change in internal energy, ΔE, for this reaction per mole of sucrose.
Why is chemistry important?
What would happen to the entropy in the reaction 203(9) ► 302(g)?
(giving away 10 points)at what position of the earth in its orbit is it summertime in the northern hemisphere Position 2 position1 position4 position3
How many moles of sodium hydroxide, NaOH, are in a 35.65 g sampleof NaOH? (The molar mass of NaOH is 40.01 g/mol.)

An element's atomic number is 63. How many protons would an atom of this element have?

Answers

Atomic number of an element correlates to the number of protons an atom of that element will have. An atom of this element would have 63 protons.

What can be determined if only the atomic number of an atom is known?(1) the total number of neutrons in the atom, only
(2) the total number of protons in the atom, only
(3) the total number of protons and the total number of neutrons in the atom
(4) the total number of protons and the total number of electrons in the atom

Answers

Answer;

(4) the total number of protons and the total number of electrons in the atom

Explanation;

-Atomic number is the number of protons in the nucleus of an atom. An atom is made up of energy shells and the central nucleus. The energy shells contains electrons that are negatively charged while the nucleus contains protons (positively charged) and neutrons (neutral).

-In a neutral atom, the number of protons and electrons are equal, thus the atomic number would indicate the number of electron and protons in an atom. The sum of protons and neutrons on the other hand gives the mass number.

It is the "(4) the total number of protons and the total number of electrons in the atom" that can be determined if only the atomic number of an atom is known.

Is a euglena abiotic or biotic

Answers

I think it is biotic. hope this helps.

Hydrogen has three isotopes 1H, 2H, and 3H. What is the difference between these three isotopes?

Answers

The main difference between the 3 isotopes of hydrogen are the number of neutrons in the nucleus. Hydrogen has no neutrons, Deuterium has one neutron, and tritium has two neutrons. All three have one proton and one electron.

35 Which element reacts with oxygen to form ionic bonds?(1) calcium (3) chlorine(2) hydrogen (4) nitrogen

Answers

$\boxed{\left( 1 \right){\text{ calcium}}}$ reacts with oxygen to form ionic bonds.

Further Explanation:

Covalent bonds are the types of bonds that involve the sharing of electrons between the bonded atoms. This bond is usually formed between two or more non-metals.

Ionic bonds are the chemical bonds that involve the transference of electrons from one atom to another. These bonds are generally formed between metals and non-metals. In these types of bonds, ions are formed by the atoms. Cations are formed by the loss of electrons and anions result from the gain of electrons.

Oxygen is a non-metal. In order to form an ionic bond with oxygen, the other element has to be a metal.

Hydrogen, chlorine, and nitrogen are non-metals so these can form covalent bonds with oxygen. But calcium is a metal and it forms ionic bonds with oxygen. Calcium loses two electrons to form ${\text{C}}{{\text{a}}^(2 + )}$ and these electrons are gained by oxygen, resulting in the formation of ${{\text{O}}^(2 - )}$ . The attraction between ${\text{C}}{{\text{a}}^(2 + )}$ and ${{\text{O}}^(2 - )}$ is an ionic bond and the resulting compound is CaO (For structure, refer to the attached image).

Learn more:

Identification of ionic bonding: brainly.com/question/1603987
What type of bond exists between phosphorus and chlorine? brainly.com/question/81715

Answer details:

Grade: High School

Chapter: Ionic and covalent compounds

Subject: Chemistry

Keywords: ionic bond, covalent bond, nitrogen, hydrogen, chlorine, calcium, oxygen, CaO, metal, non-metal.

Calcium is the element that reacts with oxygen to form an ionic bond. Calcium forms the ionic compound calcium oxide with oxygen. Hydrogen, chlorine, and nitrogen do not typically form ionic bonds with oxygen.

The element that reacts with oxygen to form ionic bonds is calcium.

Calcium (element #20 on the periodic table) readily reacts with oxygen to form calcium oxide, which is an ionic compound. In this reaction, calcium loses two electrons to become Ca2+, and oxygen gains two electrons to become O2-. This transfer of electrons creates an ionic bond, which is a type of chemical bond.

Hydrogen, chlorine, and nitrogen do not typically form ionic bonds with oxygen under normal conditions. Hydrogen forms covalent bonds with oxygen to create water, whereas chlorine and nitrogen mostly form covalent bonds.

Learn more about Ionic bonds here:

brainly.com/question/18297125

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2.0 cm + 2.6 cm + 4.2 mm =

Please show work

Answers

Hi ;)!
So:
4.2 mm (/10) = 0.42 cm

2.0 cm + 2.6 cm + 0.42 cm = 5.02 cm ;)

Other Questions

2Mg + O2 --> 2MgO Magnesium is the oxidizing agent and is reduced oxidizing agent and is oxidized reducing agent and is reduced reducing agent and is oxidized

2MgO à 2Mg + O2 is an example of a _________ chemical reaction.a. synthesis b. combustion c. replacement d. decomposition

Which statement best describes the light that will cause emission of electrons from a given metal through the photoelectric effect?light with any intensity below a certain frequency light with any intensity above a certain frequency light with any frequency below a certain intensity light with any frequency above a certain intensity

CHEMISTRYWhich of the following properties of an element is least likely to change with beta decay? A. the mass number B. the period number C. the atomic number D. the name of the element When a nucleus has too many protons, it can absorb an electron and create _________. A. a proton B. a neutron C. an electron D. an alpha ray Which of the following occurs in beta decay? A. A neutron of an atom emits a high energy proton. B. A neutron of an atom emits a high energy electron. C. An electron of an atom emits a high energy proton. D. A neutron of an atom emits a second high energy neutron. What kind of ray is given off after electron capture? A. a beta ray B. a delta ray C. an alpha ray D. a gamma ray