Answer:
due to the formation of an oxide or hydroxide layer
Explanation:
magnesium is a reactive metal...when left in air it reacts with oxygen to form an oxide layer of MgO and it can react with moisture to form Mg(OH)2 LAYER ON THE SURFACE.
What is the formula for the compound?
Answer:
the correct answer is CO2 (the last one)
Is oxygen ionic or molecular
Answer:
morlecular element is oxygen
Zn-71 has a half life of 2.4 minutes. If one had 100g at the beginning, how many grams would be left after 12 minutes?
3.125g
Explanation
2.4 minutes = 1 half life
so 12 minutes = 5 half lives (12/2.4)
100g/2 = 50g (1 half life)
50g/2 = 25g (2 half lives)
25g/2 = 12.5g (3 half lives)
12.5g/2 = 6.25g (4 half lives)
6.25g/2 = 3.125g (5 half lives)
Why are unbalanced equations NOT useful in
chemistry?
Answer:
If the numbers of each type of atom are different on the two sides of a chemical equationExplanation:
To find the number of neutrons in a atom, you subtract the number of_____ from the mass number.
You can simply subtract the atomic number from the mass number in order to find the number of neutrons.
Name two elements that have the same properties as sodium (Na)
Answer: Any Alkali metal
Explanation:
T he cool thing about the periodic table is the way it is organized. You can find chemical with similar properties is just looking in the column they are in in to determine the answer. Since Na is in the first column, any of these answer can work:
Li, K, Rb, Cs, and Fr
Is metal defined as an element or as a compound or as a material?
Answer:
element
Explanation:
A metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons
Answer:
Metal is an element because it consist of type of atom and can't be divided into other substance .
In a chemical change energy can be ___?
A. Created but not destroyed
B. Either created or destroyed
C. Destroyed but not created
D. Neither created nor destroyed
Answer:
chemical change energy can neither be created nor destroyed.
Explanation:
the rule of law of conversion states that energy can only be converted from said energy to another. it cannot be created and destroyed.
Answer:
D. Neither created nor destroyed
Explanation:
The law of conservation of energy states that energy is neither created nor destroyed.
Why do different places on Earth have different climates?
Your answer should include 1 paragraph to explain the claim, evidence, and reasoning. Be sure to check your grammar and spelling!
First, the amount of sunlight received at a given latitude is important. At the equator, the sun is high in the sky and thus very intense. As you move away from the equator, the sun does not reach as high of an angle in the sky, and is less intense. Another important effect near the poles is that during the summer, the sun is up all the time, which boosts the total amount of sunlight received in a day, while in contrast, during the winter, no sunlight is received at all.
There is another, more subtle effect that has to do with latitude. Nature likes to have the temperature be the same everywhere, much like ice cream melts at room temperature or a hot cup of coffee cools to room temperature. The equator is getting blasted with intense sunlight, while the poles are getting a lot less. Nature tries to resolve this imbalance and make the atmosphere the same temperature everywhere. The most efficient way to transfer heat towards the poles depends on latitude and the rotation of the Earth in a complex way. In the tropics (within 30 degrees latitude of the equator), the average daily temperature is mostly constant. Whether you move from north to south, say fro the equator to Mexico, the temperature is mostly the same. Compare that to the midlatitudes (30–60 degrees latitude), where the temperature changes rapidly as you move north or south to the poles. For example, the temperature in Texas is a lot hotter than the temperature in North Dakota.
Another factor is the composition of the surface. Different substances absorb, store, and re-emit heat with different levels of efficiency. The ocean is a major factor, which can either warm or cool the adjacent land. Other surface materials like rock, sand, vegetation, and ice also regulate temperature
The elevations of the surface, specifically mountains effect the climate. Usually, the taller the mountain, the colder the temperature is at the top. Mountains also cause air to flow in certain ways around them, which leads to wet areas on the upwind side and dry areas on the downwind side.
Ca+P criss cross method
Answer:
[tex]t \o \: know \: the \: answer \: [/tex]
[tex]refer \: to \: the \: attatchment[/tex]
Explanation:
Hope this helps !!why does fluorine have the highest electronegativity
Answer:
Because it only needs one more electron to get to a full valence shell (8), so it really wants it and is pulling other electrons in. It also has to do with needing one more electron to fill the 2p shell. It is a small element which means its electrons are pulled tightly to the nucleus.
Hope this helps!
Explanation:
is seafloor spreading is beneficial or harmful for the earth
Answer:
Yes
Explanation
I learned it in science class
what makes matter change from one state to another?
Answer: Adding or removing energy from matter
Explanation:
SCIENCE
the different modes of reproduction in animals such as butterflies, mosquitoes, frogs, cats, and dogs (sexual and asexual) a. Cut and paste pictures of animals and their young that are reproduced sexually(cats, dogs, etc.) b. Cut and paste pictures of animals and their young that are reproduced asexually(butterflies, mosquitoes
pls help me! i need help i will brainlies the good answer! answer this now pls! today is the deadline!
Ans: Dogs, cats, frogs, butterflies, mosquitoes, and many other animals reproduce by sexual reproduction. Animals have gonads, organs that produce egg or sperm.
a. Cut and paste pictures of animals and their young that are reproduced sexually(cats, dogs, etc.) ???Ans: your answer is in above
b. Cut and paste pictures of animals and their young that are reproduced asexually(butterflies, mosquitoes) ????Ans: your Answer is in above
How are osmosis and facilitated diffusion similar?
Answer:
I think it's is because during osmosis because when the cell duplicates in osmosis it divides into two smaller daughter cells; in diffusion there is a higher concentration near where it is but its getting smaller particles from where the source is
Sodium has a density of 1.95 g/mL If the volume of some sodium is 9.0 L what is the mass
Answer:
17550g
Explanation:
You want to use the equation D=M/V. You are given density in g/mL, so you just need to multiply that by 9L, but first you want the mL and L to match, so you change the 9L to 9000mL (knowing there is 1000mL in 1L). Then solve algebraically by multiplying the 9000mL and the 1.95g/ml, making the mL cancel, leaving you with your answer in grams.
Hope this helps!
What is the mass of 0. 513 mol Al2O3? Give your answer to the correct number of significant figures. (Molar mass of Al2O3 = 102. 0 g/mol) 0. 513 mol Al2O3 = g Al2O3.
The mass of a 0.513 mol of Al2O3 is 52.33g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the molar mass of the substance by its number of moles. That is;
mass of Al2O3 = no. of moles of Al2O3 × molar mass of Al2O3
According to this question, there are 0.513 moles of Al2O3.
Mass of Al2O3 = 0.513 × 102
Mass of Al2O3 = 52.33g
Therefore, the mass of a 0.513 mol of Al2O3 is 52.33g.
Learn more about mass calculations at: https://brainly.com/question/8101390?referrer=searchResults
mixing calcium chlorine with water is a chemical or physical change?
Answer:
Physical Change
Explanation:
Compare sodium and silver before and after they are placed in water. Has a new substance been produced in each case?
Answer:
Sodium is placed in group 1 of the periodic table of Alkali metals, and has a valence shell with one electron, making them very reactive. When placed in water, it disperses heat and begins to ignite and burn (due to its very reactive nature), resulting compound is hydrogen gas (H2), and a very strong base (Sodium Hydroxide, NaOH) used for cleaning appliances and for neutralizing agents.
Silver is placed on the transitional metal section of the periodic table, not quite reactive but is the most conductible element on the planet, is malleable and ductile. Due to it being costly and its rarity, it's not relied on for computer parts or wires. Silver doesn't actually directly react with water in its liquid state. It does produce hydrogen gas and Silver Oxide when reacting with water vapour.
In short, Sodium and water create new products, while Silver and water (only in water's gaseous form) form different products.
Do you feel that this equation is currently following the law of conservation of mass?
N2 + H2 → NH
Answer:
N2 + H2 --> 2 NH
Explanation:
You need to add 2 to make it correct
Find the unit price: 12 eggs for $3. How much is the cost per (one) egg?.
it's 3 dollars per 12 eggs so 3/12
simplify 3/12 by dividing both numbers by 3 so you get 1/4
you should know what 1/4 of a dollar is
or think of it this way 12 eggs are 3 dollars so every 4 eggs is one dollar. divide 1 dollar by 4 eggs
Figure 2
Describe how a dog grows. Describe their mode of reproduction
Explanation:
Although all puppies are officially considered adult dogs once they reach one year old, puppies continue to grow in height and size while their bones are still developing, which takes anywhere from 6 to 24 months. Their skeletal growth is what determines how tall they will become as adults.
help plz I don't understand the last 2 questions
Answer:
b) (i): 0.91 Amgstroms
(ii): 9.1 × 10^-11 Angstroms
(c): Volume = 20 Angstroms
Explanation:
• Let's first convert the units:
[tex]{ \rm{1 \:nanometre = 1 \times {10}^{ - 9} \: metres} } \\ { \rm{10 \: angstroms = 1 \times {10}^{ - 9} \: metres}} \\ { \rm{1 \: micrometer = 1 \times {10}^{ - 6} \: metres = 1000 \: nm}} \\ \\ { \rm{1 \: {nm}^{3} = 1000 \: {angstroms}^{3} }}[/tex]
Question (b)
(i)[tex]{ \rm{radius = \frac{diameter}{2} }} \\ \\ { \rm{radius = \frac{0.182}{2} }} \\ \\ { \rm{radius = 0.091 \: nm}} \\ \\ { \mathfrak{ answer{ : { \rm{radius = (0.091 \times 10) \: angstroms}}}}} \\ \\ { \rm{radius = 0.91 \: angstroms}}[/tex]
(ii)[tex]{ \rm{radius = 0.091 \: nm}} \\ \\ { \rm{radius = 0.091 \times( 1 \times {10}^{ - 9} ) \: metres}} \\ \\ { \rm{radius = 9.1 \times {10}^{ - 11} \: m }}[/tex]
(c)[tex]{ \rm{volume = (0.5 \times 0.2) \: nm \times 0.0002 \: micrometer}} \\ \\ { \rm{volume = 0.5nm \times 0.2nm \times (0.0002 \times 1000)nm}} \\ \\ { \rm{volume = 0.5 \times 0.2 \times 0.2 \: nm {}^{3} }} \\ \\ { \rm{volume = 0.02 \: nm {}^{3} }} \\ \\ { \rm{volume = (1000 \times 0.02) \: angstroms {}^{3} }} \\ \\ { \rm{volume = 20 \: angstroms}}[/tex]
What is held together by a metallic bond?
Answer:
metallic bond, force that holds atoms together in a metallic substance. The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.
Explanation:
What does the law of conservation of matter state?
a Matter can be created, destroyed, and changed.
b Matter can be destroyed and created, but not changed.
c Matter can be changed, but not created or destroyed.
d Matter can be created and changed, but not destroyed.
The answer is c. Matter can be changed, but not created or destroyed.
Name the following molecule in the image
[tex]\\ \sf{:}\longrightarrow 2,4-diethyl-2-methylpentane[/tex]
2. Which substance will form a solution with water? (Select all that app
string
sand
sugar
salt
Answer:
sugar and salt, as they can dissolve in water. Sugar and salt have a high solubility in water. So, sugar and salt can form a solution with water.
Explanation:
I NEED MORE HELP ASAPP
Answer:
1) Gas
2) Higher
3) Increases
4) Higher
Explanation:
pls answer this it's due today
Answer:
That's pretty easy,if you have a grasp of Elements, Compounds and their Symbols ans Molecular formula.
So, Let's get started!
Our reactions are as follows:
Sodium(Na) + Chlorine(Cl) ---> Sodium chloride(NaCl)Think of a compound that has both Sodium and Chlorine and is very common.
Common salt — Sodium chloride!
Yeah, that's it! It has both Sodium and Chlorine in it's molecular formula. (NaCl)
Magnesium(Mg) + Oxygen(O2) ---> Magnesium oxide(MgO)Now, we have to, somehow, get Magnesium oxide using Oxygen. The best way is: by reacting Magnesium with Oxygen.
Iron(Fe) + Sulfur(S) ---> Iron Sulfide(FeS)Now, we have to get two reactants that react to form Iron Sulfide.
FeS contains only two elements in its formula and that are: Iron(Fe) and Sulfur(S).
So, the best way would be to react Iron(Fe) and Sulfur(S) and get Iron Sulfide (FeS)
Hydrogen(H2) + Oxygen(O2) ---> water(H2O)You must know that water is H2O, that is, a compound of Hydrogen and Oxygen, the easiest way to get H2O as your product would be : by reacting Oxygen and Hydrogen.
how molecular structure affects solubility?
Answer:
The molecular structure affects solubility mainly biased on its polarity or bonded ions.
Explanation:
Polar molecules will better interact with the water molecules and will dissolve easier. Nonpolar molecules can dissolve if they are small enough, however they don't interact well with the polar molecules. Bonded ions, such as NaCl split into a cation Na and an anion Cl which the positive charge on the Na will be attracted to the oxygen, and the negatively charged Cl will be attracted to the positive Hydrogen.
**Remember this rule, like dissolves like, meaning nonpolar dissolves nonpolar and polar dissolves polar.
I hope this helps!