Answer: Reflectors use a mirror to collect the light, whilst refractors use a lens while, Refractor telescopes require a large lens at the front to direct the incoming light to the lens.
Which of the following is a scientific question?
O A. Who made the first plant-hardiness zone map?
O B. Which plants are sold by my local nursery?
O c. Which kind of flowers should I plant in my garden?
O D. How does gravity affect the growth of plant roots?
At 25ºC, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 kPa. Then the gas is compressed to a volume of 80. ML. What is the new pressure of the gas if the temperature is held at 25ºC?
Answer:
P2 = 226.6 kPa (Approx)
Explanation:
Given:
Temperature t = 25ºC
Old volume v1 = 145 ml
Old pressure p1 = 125 KPa
New volume v2 = 80 ml
Find:
New pressure p2
Computation:
p1v1 = p2v2
125 x 145 = P2 x 80
P2 = 226.6 kPa (Approx)
Please help i will give brainliest
The speed of a mechanical wave through a medium depends on the type of medium. It also depends on the type of mechanical wave. Which statement is true?
The statements are;
A) All waves travel at the same speed if no medium is present.
B) Electromagnetic waves require a medium, but mechanical waves do not.
C) All waves travel at the same speed through any medium.
D) Mechanical waves require a medium, but electromagnetic waves do not.
Answer:
Statement D is true.
Mechanical waves require a medium, but electromagnetic waves do not.
Explanation:
The two types of waves are;
Mechanical waves and Electromagnetic waves.
Mechanical waves require a medium, such as an atmosphere or water, to enable it transport its energy. For example sound waves occur when you clap and thereby distort the air around.
Whereas, Electromagnetic waves do not require a medium to enable it transport its energy. A good example would be light. Normally, Electromagnetic waves are usually formed when the electric field and the magnetic field are perpendicular to each other.
So electromagnetic waves can transmit without a medium because electric and magnetic fields can exist independently without a medium.
Question 2 (1 point)
Which of the following is the main reason the transition metals are able to exist in different forms?
а.
predictability in ability to bond
B.
unfilled d orbitals
C.
magnetic properties
D.
predictability in number of valence electrons
Answer:
B. Unfilled d orbitals
Explanation:
A student weighed an empty graduated cylinder. It weighed 35.86 g. She then carefully added water to the graduated cylinder until it reached the 7.5 mL mark. When she weighed the graduated cylinder again, this time with the 7.5 mL of water in it, it weighed 43.18 g. What was this student's experimental density of water? A relationship between the number of pennies and density
Question:
A student weighed an empty graduated cylinder. It weighed 35.86 g. She then carefully added water to the graduated cylinder until it reached the 7.5 mL mark. When she weighed the graduated cylinder again, this time with the 7.5 mL of water in it, it weighed 43.18 g. What was this student's experimental density of water?
Answer:
0.976 g/mL
Explanation:
Weight of empty cylinder = 35.86g
Volume of water = 7.5mL
Weight of cylinder + water = 43.18g
Experimental density = ?
Density of water = Mass of water / volume of water
Mass of water = (Weight of cylinder + water) - Weight of empty cylinder
Mass of water = 43.18 - 35.86 = 7.32g
Density = 7.32 / 7.5 = 0.976 g/mL
If an atom has a diameter of 395 pm,
what is its radius?
Answer:
197.5pm
Explanation:
Given parameters:
Diameter of the atom = 395pm
Unknown:
Radius of the atom =?
Solution:
Radius is the half of diameter;
Radius = [tex]\frac{diameter}{2}[/tex]
Radius = [tex]\frac{395}{2}[/tex] = 197.5pm
describe how metamorphic rocks are formed by heat and pressure
Answer:
Metamorphic rocks form when heat and pressure transform an existing rock into a new rock. Contact metamorphism occurs when hot magma transforms rock that it contacts. Regional metamorphism transforms large areas of existing rocks under the tremendous heat and pressure created by tectonic forces.
Explanation:
P and Q are two substances such that the melting point of P and the boiling point of Q are the same. If P is a solid at a certain temperature, what state will Q be in at the same temperature?
Answer:
Explanation:
Firstly, it should be noted that melting and freezing points are the same. Thus, when a substance melts at a certain temperature, it means it can also start freezing/solidifying at that same temperature. That been said, when the substance P is a solid at a certain temperature, the other compound Q will boil at that same temperature and hence will be a gas at that same temperature.
If P is solid, it simply means that Q must still be in the liquid state.
From the question, we can see that, the melting point of P and the boiling point of Q are the same. The melting point of a substance is the temperature at which the solid turns to liquid while the boiling point of a substance is the temperature at which a liquid turns to a gas.
If P is solid, it simply means that Q must still be in the liquid state. It has not yet started boiling since the melting point of P and the boiling point of Q are the same.
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how many sig figs are in 1.008 and 120.9??
Answer:
there are 4 sig figs in 120.9 and there are 4 sig figs in 1.008
Explanation:
The growth of a plant toward light is called _____.
phototropism
tropism
geotropism
It's called phototropism
Answer:
The answer is (Phototropism)
What do ionic bonds contain?
Answer:
Valence Electrons
Explanation:
Answer:
Ionic bonds contain electrovalent bond
Explanation:
Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.
Can the process of rusting be called combustion?
Answer:
no the answer is oxidation
brainly is so boring like upgrade it to be better or something
Answer:
ya same here i hope so btw
Answer:
my guy, this is for school. school is boring as it is, be grateful they even provide the service they provide. cause i know for a fact if you if your using brainly, you also need help. maybe you need to upgrade to the tutor plan, someone like you needs hands on learning.
Explanation:
common sense
How many phases of matter are there? two, three, four or five?
Answer:
There are four phases of matter.
Explanation:
There are the three phases you normally hear about: solid, liquid and gas.
However, there is also a fourth named plasma.
PLS GIVE BRAINLIEST
Which of the following is a difference between naming ionic and covalent compounds?
Group of answer choices
In ionic compounds the ending of the second element changes to -ide, but not in covalent compounds.
In covalent compounds, the prefix of the first element is always ignored but the prefix in the second element depends on the subscript of the element. In ionic compounds, the subscript on each element does not affect the name of the compound.
In covalent compounds the ending of the second element changes to -ide, but not in ionic compounds.
In covalent compounds, the prefix of the first element and second element depends on the subscript of each element. In ionic compounds, the subscript on each element does not affect the name of the compound.
The difference between naming ionic and covalent compounds is that, in ionic compounds the ending of the second element changes to -ide, but not in covalent compounds.
Ionic compounds are compounds that are formed by the by the transfer of electrons from a metal to a nonmetal. Covalent compounds are formed when electrons are shared between nonmetals.
For ionic compounds, the name of the second element(the nonmetal) often ends in -ide. For instance; sodium bromide, cesium oxide and potassium nitride. This does not apply when naming covalent compounds. The are named based on the subscripts of each element in the compound.
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CO2(g) +H2(g)------>CO(g) + H2O(/)
What is being oxidized?
Carbon
Carbon Dioxide
Oxygen
Hydrogen
Answer:
Srry its so hard
Explanation:
Here is the electron configuration for Magnesium. How many total electrons are in the 2nd energy level?
Mg: 1s2 2s2 2p6 3s2
Answer:
8 electrons
Explanation:
Magnesium is present on group 2.
It has 2 valence electrons.
Electronic configuration of magnesium:
Mg₁₂ = 1s² 2s² 2p⁶ 3s²
1st energy level contain 2 electrons.(1s²)
2nd energy level contain 8 electrons. (2s² 2p⁶)
3rd energy level contain 2 electrons. (3s²)
3rs energy level of magnesium is called valence shell. It contain two valance electrons. Magnesium can easily donate its two valance electrons and get stable electronic configuration.
It react with halogens and form salt. For example,
Mg + Cl₂ → MgCl₂
1. How many times will a mole of paperclips (think giant paperclip chain) stretch around the equator of the
earth? (1 paperclip = 0.030 m, Earth's circumference = 4.00 x 10m)
Which of the following most likely happens when thermal energy is removed from a chemical reaction?
Answer:
fewer collisions occur between particles or lowering the temperature
Explanation:
What are the first two levels of cellular organization?
Answer:
Cells and tissue
Explanation:
Cells are the smallest functional units of all living things
Tissue is organic material from which organs and their bodily structures appear
HELP PLEASE!!!!!!!!
What is the half life of quartz??
Answer:
1.36 Myr or 717 kyr.
Explanation:
Answer:
Half life of quartzs means natural decay of radioactive material.
Explanation:
collectiveness leads to a good society? how
Answer:
A good society has a transparent talk, they share all matters related to the society, hence everyone knows what's going on. This is why collectiveness leads to a good society.
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Which equation represents a double replacement reaction?
A) 2 Na + 2 H2O → 2 NaOH + H2
B) CaCO3 → CaO + CO2
C) LiOH + HCl → LiCl + H2O
D) CH4 + 2 O2 → CO2 + 2 H2O
Answer:
C) LiOH + HCl → LiCl + H₂O
General Formulas and Concepts:
Chemistry - Reactions
Synthesis Reactions: A + B → AB Decomposition Reactions: AB → A + B Single-Replacement Reactions: A + BC → AB + C Double-Replacement Reactions: AB + CD → AD + BCExplanation:
Step 1: Define
RxN A: 2Na + 2H₂O → 2NaOH + H₂
RxN B: CaCO₃ → CaO + CO₂
RxN C: LiOH + HCl → LiCl + H₂O
RxN D: CH₄ + 2O₂ → CO₂ + 2H₂O
Step 2: Identify
RxN A: Single Replacement Reaction
RxN B: Decomposition Reaction
RxN C: Double Replacement Reaction
RxN D: Combustion Reaction
what coefficient will go in the box
Answer:
5
Explanation:
I don't remember very thing from this unit but I believe 5 makes it possible
I need help can someone please explain to me why this B is the correct answer I have a photo of the question
I know B is the correct answer I just need help knowing why it’s B
Answer:
9 g
Explanation:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
4 16 11 9
4+16 = 20 11+9 = 20
9 gram of water must be produced because according to law of conservation of mass, mass neither created nor destroyed thus on both side of equation mass must be same.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
If a substance has a PH of 7 is it a acid, base or a neutral.
Answer:
Neutral
Explanation:
A pH below 7 is acidic and a pH above 7 is basic, and a pH of 7 is neutral.
What are the single sugars that are the building blocks of carbohydrates?
Answer:
Monosaccharides, these are the simplest building block of carbs
Explanation: