a major use of magnesium oxide is as a refractory material.
explain in terms of structure and bonding, why magnesium oxide has a very high melting point.
[ this is 4 marks, please provide a good answer ]
[ giving brainliest + thanks on profile ]
Sodium oxide has a high melting point because of the strength ofits bonds. Due to having strong bonds, they cannot be broken veryeasily. Magnesium chloride is ionic compound. There is a strong electrostatic force of attraction between 2 chloride atoms and 1 magnesium atom.
Because it retains its strength at very high temperatures. It is considered a refractory material with a melting point of 6500 degrees F. It is also very non-reactive with other materials that might be put into the furnace and is even used to make crucibles - containers used to melt other substances.
i need help w this..
A pneumonic device is a memorization tool that helps you remember things. For example, if you can read music you probably have heard, “Every Good Boy Does Fine” to learn the names of the lines on the treble clef EGBDF. Or maybe your math teacher taught you, “Please Excuse My Dear Aunt Sally,” to help you remember the order of operations. It is now your turn to think of a pneumonic device to remember the water cycle in order. Write your pneumonic device below.
What type of electromagnetic energy does a light use?
Answer:
electromagnetic radiation
Explanation:
electromagnetic radiation: Energy that travels as a wave, including forms of light. Electromagnetic radiation is typically classified by its wavelength. The spectrum of electromagnetic radiation ranges from radio waves to gamma rays. It also includes microwaves and visible light.
water evaporates and becomes a gas when from the sun
Answer:
water vapour
Explanation:
water vapour condents to water/rain
HELP NEED THIS DONE BEFORE 9:45!!!!!!!!!!!!!!!! WILL GIVE 100 POINTS AND BRAILIEST IF DONE BEFORE 9:45!!!!!!!!!!!!!
Answer:
1.) 742.57 m/s
2.) 132
3.) 4.375 hours
4.) 1080
5.) 81.6 km per hour
6.) 20 min = 1,200 secs1000 / 1200
Explanation:
Your Welcome!
Answer:
1.) 742.57 m/s
2.) 132 m
3.) 4.375 hours
4.) 1080 m
5.) 81.6 km per hour
6.) 20 min = 1,200 secs1000 / 1200
Explanation:
**Brainliest would be appreciated**
Which two substances are among the four major types of organic compounds made by living things?
A. Phosphates
B. Nitrates
C. Proteins
D. Lipids
Answer:
Lupids
Explanation:
D:)
How is a mixture such as a plate of pasta different from a mixture such as air
Answer:
Well there is a lot of differences between the two. Its called homogeneous and Heterogeneous mixtures. Homogeneous mixtures are all the substances are evenly distributed throughout the mixture (salt water, air, blood). Heterogeneous mixtures are the substances that are not evenly distributed (chocolate chip cookies, pizza, rocks). So Pasta with sauce and meatballs is heterogeneous and air is homogeneous
HOPE THIS HELPS HAVE A GREAT DAY!!~
Explanation:
How does this support the theory that whales evolved from walking mammals? in embryo evidence
Answer:
A embryo's, Whales have small back limbs which disappear before birth.
Explanation:
There are lots of evidence in a whale's body and biology suggesting its ancestors lived on land. They have paddle-shaped flippers that encase hand bones with five 'fingers,' and they breathe air and feed their young with their own milk.
THIS IS SCIENCE If you answer this please make two sides or list which go on each one whether it is Terrestrial or Jovian. I will give brainliest!
Compare terrestrial and Jovian planets below by writing each characteristic in the correct
category.
• less massive
• more massive
• many moons
• smaller volume
• zero to two moons
• farther from the Sun
• some contain ring systems
• larger volume
• closer to the Sun
• composed mostly of gases
• longer revolutionary period
• shorter revolutionary period
• composed of silicate rocks and metals
• geologic features like craters and mountains
Answer:
geologic features like craters and mountains
Explanation:
when i did this my teacher said it was ok
A foil boat measures 4.0cm by 5.0cm and has a mass of 100.0g. If you put the boat in water, how far will it sink? (Recall the density of water is 1.0 g/mL) (answer with a number; units are cm)
Answer:
Let the volume of the block of wood be
V
c
m
3
and its density be
d
w
g
c
m
−
3
So the weight of the block
=
V
d
w
g
dyne, where g is the acceleration due to gravity
=
980
c
m
s
−
2
The block floats in liquid of density
0.8
g
c
m
−
3
with
1
4
t
h
of its volume submerged.So the upward buoyant force acting on the block is the weight of displaced liquid
=
1
4
V
×
0.8
×
g
dyne.
Hence by cindition of floatation
V
×
d
w
×
g
=
1
4
×
V
×
0.8
×
g
⇒
d
w
=
0.2
g
c
m
-3
,
Now let the density of oil be
d
o
g
c
m
-3
The block floats in oil with 60% of its volume submerged.So the buoyant force balancing the weight of the block is the weight of displaced oil =
60
%
×
V
×
d
o
×
g
dyne
Now applying the condition of floatation we get
60
%
×
V
×
d
o
×
g
=
V
×
d
w
×
g
⇒
60
100
×
V
×
d
o
×
g
=
V
×
0.2
×
g
⇒
d
o
=
0.2
×
10
6
=
1
3
=
0.33
g
c
m
−
3
Explanation:
Which of these shows the common stages of growth for a flowering plant?
leaves, seed, shoot, root system, stem or trunk, flowers
stem or trunk, root system, seed, shoot, leaves, flowers
seed, shoot, root system, stem or trunk, leaves, flowers
flower, seed, shoot, stem or trunk, root system, leaves
Answer:
everything because every part are equally responsible for the growth of plant
Please help!!
What do scientists do when they want to name a new organism?
all of the above
They see how the organism is similar to other organisms.
They see if the organism has the characteristics of an animal or plant.
They look at what makes the organism unique.
Answer:
All of the above
Explanation:
I believe all three are true. They see how the organism is similar to other organisms. They see if the organism has the characteristics of an animal or plant. They look at what makes the organism unique.
When excess _____ flow into an aquatic ecosystem, a chain of events may take place which leads to a low dissolved-oxygen level in the water. This is called eutrophication.
Group of answer choices
nutrients
gas particles
water and sand
solid substances
Answer:
solid substances
Explanation:
How do the data support your claim above?
Explain your statement above. Be sure to refer to specific pieces of data from your experiment that support your argument.
Answer:
i need more information give me more pictures
Explanation:
lol
Answer:
the data will support my theory if the results are right for my hypothisis
Explanation:
Match the term with its description.
Acid:
Base:
Ions:
pH:
Definition:
A value from 0 to 14 is used to specify how acidic or basic a compound is when it is dissolved in water
Used to measure the pH of substances by determining their hydrogen ion concentration
A compound that increases hydroxide ions (OH−) when it is dissolved in a solution
A compound that increases hydrogen ions (H+) when it is dissolved in a solution
A value from 0 to 14 is used to specify how acidic or basic a compound is when it is dissolved in water= pH
A compound that increases hydroxide ions (OH−) when it is dissolved in a solution= Acid
A compound that increases hydrogen ions (H+) when it is dissolved in a solution= ions
Used to measure the pH of substances by determining their hydrogen ion concentration= base
Answer: pH goes with A value from 0 to 14 is used to specify how acidic or basic a compound is when it is dissolved in water
base goes with A compound that increases hydroxide ions (OH−) when it is dissolved in a solution
ions goes with Used to measure the pH of substances by determining their hydrogen ion concentration
acid goes with A compound that increases hydrogen ions (H+) when it is dissolved in a solution
Explanation: i took the test and got it right
The brain, spinal cord, and nerves are all major organs of the ___ system.
Answer:
nervous system
Explanation:
nervous system
nervous systemsystemsystem
A soft lump of clay has water run on top of it. Most of the water and clay runs off the table. After a long while, the water is turned off and allowed to dry. There is no clay left; instead, there are small pebbles and other types of components left on the table.
Which natural process is this modeling?
A. physical weathering
B. deposition
C. erosion
D. chemical weathering
Why does the Earth experience two high and two low tides each day?
The moon orbits the Earth twice as fast as the sun.
The moon orbits the Earth completely once per day.
The moon and the sun create their own high and low tides.
The moon passes over the same location above the Earth's surface twice per day.
What is the working resistance of a bulb that takes a current of 0.25 A when it is connected to 220V mains supply?
Answer:
880 Ω (Ohms)
Explanation:
To calculate Resistance from Potential Difference (Volts) and Current (Amps), you use the equation R = V/I
So,
R = 220/0.25
R= 880
Below are atomic-scale models of two different substances. Use the terms in the word bank to label these models. Use each of the terms only once.
Top box :-
Denoted to one ClHence it should be atom
#Top right box
Denoted to KCl and CH_4 moleculesHence answer should be molecules
#Bottom left:-
Denoted to Whole branching of KCl h.ce it's repeating atom group
#Last
CH_4 's extended structure is shown hence it's extended structure
Which two substances are among the four major types of organic compounds made by living things?
A. Phosphates
B. Nitrates
C. Proteins
D. Lipids
Answer:
Lipids
Explanation:
D:)
Answer:
Lipids and Proteins
Explanation:
Hope this helps <3
Estimate the length of a baseball bat and mass of a baseball in SI units. How can you check how close your estimates are?
Answer: You need the mass of the bat and the length in some-type of units.
Explanation:
What happens to an object if the total of the forces acting on it are greater than zero?
Select one:
Nothing will happen to the object.
The object’s motion will change.
The object will move forward.
The object’s motion will remain the same.
What do you think happens to the oxygenated blood after it enters the left ventricle?
Explanation:
The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium. From the left atrium blood flows into the left ventricle.
can someone help me w this? A pneumonic device is a memorization tool that helps you remember things. For example, if you can read music you probably have heard, “Every Good Boy Does Fine” to learn the names of the lines on the treble clef EGBDF. Or maybe your math teacher taught you, “Please Excuse My Dear Aunt Sally,” to help you remember the order of operations. It is now your turn to think of a pneumonic device to remember the water cycle in order. Write your pneumonic device below.
Water cycle stages: Evaporation, Transpiration, Condensation, Precipitation
Edward took Charlie's pencil
A person riding a bicycle wants to move the bicycle forward. She moves her legs up and down on the bicycle's pedals. Then the rider wants to stop the bicycle. She stops pedaling and the bicycle slows. She takes one of her feet off a pedal and puts her foot on the ground to stop the bicycle and stay upright.
Which of these best identifies a pathway of systems in the rider's body, as described in this scenario?
A person riding a bicycle wants to move the bicycle forward. She moves her legs up and down on the bicycle's pedals. Then the rider wants to stop the bicycle. She stops pedaling and the bicycle slows. She takes one of her feet off a pedal and puts her foot on the ground to stop the bicycle and stay upright.
Which of these best identifies a pathway of systems in the rider's body, as described in this scenario?
nervous system > musculoskeletal system > circulatory system > nervous system
musculoskeletal system > nervous system > circulatory system > musculoskeletal system
musculoskeletal system > circulatory system > musculoskeletal system > nervous system
nervous system > musculoskeletal system > nervous system > musculoskeletal system
Answer:
nervous system>musculoskletal system>circulatory system>nervous system
Explanation:
when salt dissolves into water does it change its state
Answer:
no it doesn't change back
fine here When you dissolve salt in water, the sodium chloride dissociates in Na + ions and Cl - ions, which may be written as a chemical equation : NaCl (s) → Na + (aq) + Cl - (aq) Therefore, dissolving salt in water is a chemical change. The reactant (sodium chloride, or NaCl) is different from the products (sodium cation and chlorine anion).
How can speed be described?
Select one:
The mass multiplied by the acceleration of an object.
The force on an object divided by the mass of an object.
The distance an object travels at a certain velocity.
The distance travelled by an object in a certain time.
Answer:
The mass multiplied by the acceleration of an object.
Explanation:
Please give brainliest, It's not much, but it's honest work.
Explain the water cycle in your own words. make sure u tell the steps in order
Answer:
Collection - Evaporation - Condensation - Precipitation
Explanation:
The Water cycle is a series of continuous events that cause rain
Which shows the classification of a human?
Animalia, Arthropoda, Insecta, Lepidoptera, Nymphalidae, Morpho, Morpho Peleides
Animalia, Chordata, Amphibia, Anura, Hlidae, Hyla, Hyla cinerea
Animalia, Chordata, Mammalia, Primate, Hominidae, Homo, Homo sapiens
Animalia, Chordata, Mammalia, Carnivora, Canidae, Canis, Canis lupis
many points.
ALSO BRAINLIEST IS HERE!
