Answer:
Because heat flows from warmer objects to cooler objects
Explanation:
equatinal by elimination melha
8n-3y = 18 and5x+6y=27
Answer:
x = 3 and y= 2
Explanation:
Given equations:
8x - 3y = 18 - ---- (I)
5x + 6y = 27 -------(II)
Solve this problem by elimination;
In the elimination method, we simply find a common term that can make one of the variables in the two equation the same. Then we either add or subtract to remove the variable.
Mulitply equation (i) by 5 to give equation III
Mulitply equation (II) by 8 to give equation IV
5(8x - 3y) = 5(18) ------- III
8(5x + 6y) = 8(27) ------- IV
40x - 15y = 90------- III
40x + 48y = 216 ------- IV
Subtract equation III and IV;
-15y - 48y = 90 - 216
- 63y = -126
y = 2
Solve for x;
40x - 15y = 90;
40x - 15(2) = 90
40x - 30 = 90
40x = 90 + 30
40x = 120
x = 3
how to determine the atomic mass?
Answer: To calculate the atomic mass add up the mass of protons and neutrons.
I hope I helped!
Noble gas configuration
Answer:
Rubidium= [Kr] 5s^1
Calcium= [Ar] 4s^2
Aluminium= [Ne] 3s^2 3p^1
Explanation:
A noble gas configuration begins with the elemental symbol of the last noble gas prior to the atom. The symbol is then followed by the remaining electrons.
Hope this helped! good luck :)
32 N of Force. 37 N force. How strong is the net force and in which direction?
Which describes the elements in a given group of the periodic table?
They decrease in atomic mass as you go down the column.
They increase sequentially in atomic number from top to bottom.
They are in the same family, with similar characteristics.
Their properties change according to a pattern as you go down the column.
Answer:
They are in the same family, with similar characteristics.
Explanation:
The elements in a given group of the periodic table are in the same family and with similar characteristics.
Vertical columns on the periodic table are referred to as a group or family. Elements having the same number of electrons in the outermost shell of their atoms are placed one another in vertical columns. Each resulting vertical column is a group or family. Elements in the same group exhibit similar chemical properties because of the same number of electrons in their atoms' valence shells.Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. Over time, other species are found in the disturbed areas, and the number of pioneer species decreases. Why does the number of pioneer species get less?
Answer:
The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.
Explanation:
Pioneer species like Lichens and Mosses inhabit an area after a major disturbance, such as a volcanic eruption. However, with time the number of pioneer species decreases.
The number of pioneer species get less as the area has more soil to support complex plants and the competition decreases the role of pioneer species.
use the Kinetic Theory to explain the following. when you come home from school and open the door you can smell your tea being cooked
Answer:
Tea is getting hot on the stove.
2) As the tea and water gets hot, some combined molecules of tea and water will escape from the teapot.
3) Those escaped molecules now have the entire free space of the entire room to float around in, which they do (because they have high kinetic energy due to being heated).
4) Hence, in this scenario, your nose will detect a few of those molecules and you smell hot or warm tea.
5) Cold tea would be a different story. Cold beverages like cold tea do not have the kinetic energy where molecules can 'break free' of the surrounding container. Someone could be sitting in the room having a can or bottle of cold tea and you would not notice that when you walked in the door.
Lime stone is a sedimentary rock that contains calcium this type of rock typically forms in warm shallow marine waters. Which process is involved in distributing calcium before it becomes part of the sedimentary rock?
A) tectonic movement
B) weathering
C) a biological process
D) volcanic activity
Answer:
the answer is B!!!
Explanation:
Given: (52.6 cm)(1.214 cm)
What is the product expressed to the correct number of significant figures?
1.
64 cm2
2.
63.9 cm2
3.
63.86 cm2
4.
63.8564 cm2
Answer:
2.
63.9 cm2
Explanation:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.06 in this number only one significant figure present which is 6.
Zero between the non zero digits are consider significant like 108 consist of three significant figures.
The zeros at the right side e.g 240000 are also significant. There are six significant figures are present.
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places. For example,
The difference between 7.69 and 4.0.
7.69 - 4.0 = 3.7
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
For example in given q:
52.6 cm × 1.214 cm = 63.9 cm²
You find a clear gem that is made of one substance. What could you do to
identify whether the gem is a diamond?
Answer:
You could have a scratch test, fog test, break test, theres many tests you could perform to see if it is a diamond.
Explanation:
A young girl has blue eyes.
Which statement explains how the young girl inherited her blue eye color?
A. The girl received proteins from her mother and father that coded for blue eye color.
B. The girl received blue pigments from her mother and father that formed her blue eye color.
O c The girl received cells from her mother and father that blended together to form her blue eye color.
D. The girl received chromosomes from her mother and father containing DNA that coded for blue eye color.
Answer:
D
Explanation:
( I hope that this helps )
Answer:
The answer is d
Explanation:
Please i need to pass this!
Please try
It is incorrect because it should have a total of eight electrons with two electrons between each H and O
Further explanationLewis structure shows the form of bonds that occur in the valence electrons of an element or compound
This bonding usually occurs in covalent bonds
Valence electrons are electrons used in a chemical bond
The main group elements usually have valence electron configurations in the ns and np subshells, While the transition elements in the subshells (n-1) d and ns.
Element O has 6 valence electrons
Element H has 1 valence electron
To achieve stability, the element O needs 2 more electrons which are obtained from 2 electrons from the H element, while the H element needs 1 electron to be stable
So that a covalent bond is formed
You are using a calorimeter to calculate the specific heat capacity of a metallic ore. The calorimeter contains 0.50 kilograms of water at room temperature (22 °C). We heat the ore in boiling water and then drop the metal into the calorimeter and wait for the water and metal to reach the same temperature. The mass of the ore is 3.5 kilograms. We find that the water has increased in temperature to 24.3 °C. Recall that the specific heat of water is 4.18 J/g–°C. Calculate the specific heat capacity of the ore.
In the calorimeter, the heat received is the same as the heat released
Q abs = Q release
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Q released by a metallic ore and absorbed by water at calorimeter
Q ore = Q water
Q waterm = 0.5 kg = 500 g
c = 4.18 J/g–°C.
Δt = 24.3 - 22 = 2.3
[tex]\tt Q=m.c.\Delta t\\\\Q=500\times 4.18\times 2.3=4807~J[/tex]
the specific heat capacity of the ore.Q ore = Q water = 4807 J
m ore = 3.5 kg = 3500 g
Δt = 100 - 24.3 = 75.7
[tex]\tt 4807=3500\times c\times 75.7\\\\c=0.018~J/g^oC[/tex]
What is the decomposition of 2LiCIO3
To compare how different types of soil absorbed water, Christian set up an experiment. He poked equal numbers and sizes of holes into the bottoms of three plastic cups. He filled one cup with sand, one with potting soil, and left one empty. He placed each cup in a stand over a beaker. Christian poured 400 mL (milliliters) of water into each of the cups. He then measured the amount of water collected in the beakers beneath each cup at 1 minute intervals for 3 minutes. What is the control in this experiment? Group of answer choices
Answer:
The empty cup
Explanation:
Got it right on the test
What is the mass of 0.250 mol of chlorotrifluoromethane, CCIF3?
A. 26.1 g
B. 104 g
C. 4.78 x 10-3 g
D. 52.2g
Answer:
26.1g
Explanation:
Cclf3
=35.5
F=54/101.5
Mass=mol*mm
=0.25*1015
=26.1g
What causes the air above a pot of boiling water to become warm?
The air transfers thermal energy to the water vapor.
The water vapor transfers thermal energy to the air.
The particles in the air lose kinetic energy.
The particles in the water vapor gain kinetic energy.
Answer: The water vapor transfers thermal energy to the air.
Explanation:
Earth's revolution takes 365.25 days. What is a revolution?
Answer:
"Revolution" refers the object's orbital motion around another object.
plz mark brainliest :DD
What is an ionic bond?
Answer:
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion
Explanation:
pleaseee mark brainliest <3!
Consider a 5.430 g mixture of FeO and Fe3O4. You react this mixture with excess of oxygen to form 5.779 g Fe2O3. Calculate the percent mass of FeO in the original mixture.
Answer:
Explanation:
A 5.430 g mixture of FeO and Fe3O4 is reacted with excess of oxygen to form 5.779 g Fe2O3. Find the masses of FeO and Fe3O4 present in the mixture.
I found the answer by doing the following:
Fe2O3 = 159.69 g/mol
FeO = 71.745 g/mol
Fe3O4 = 231.535 g/mol
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
x + y :rarrow: 0.03619 mol Fe2O3, where x = FeO and y = Fe3O4.
This implies that y = 0.03619 - x.
5.430 g = x*71.745 g/mol + (0.03619 - x)*231.535g/mol
x = 0.01846 mol * 71.745 g/mol = 1.324 g FeO
y = 0.03619 - 0.01846 = 0.01773 mol * 231.535 g/mol = 4.105 g Fe3O4
My question is why doesn't the following work:
4FeO + O2 :rarrow: 2Fe2O3
4Fe3O4 + O2 :rarrow: 6Fe2O3
_______________________
2FeO + 2Fe3O4 + O2 :rarrow: 4Fe2O3
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
Product:reactants in question are in a 2:1 ratio as given by the stoichiometric coefficients.
0.03619 mol / 2 = 0.01810 mol of FeO and 0.01810 mol Fe3O4.
0.01810 mol FeO * 71.745 g/mol = 1.299 g FeO
0.01810 mol Fe3O4 * 231.535 g/mol = 4.191 g Fe3O4
Obviously this doesn't work because the original mixture is 5.430 g and not 1.299 g + 4.191 g = 5.490 g. Why doesn't this work the way I think it should? Thank you.
how do you write out 4,5-dimethyl-4-octene
you can see the answer at the pic
Which type of matter cannot be broken down into simpler substances by a chemical change?
A. an element
B. a mixture
C. a solution
D. a compound
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. An element cannot be broken down into simpler substances by a chemical change. The correct option is option A.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Element is the basic unit of any compound and molecule which can not be broken further. Mixture, solution and compound are composed of two or more than two elements which can be further broken down easily.
Therefore, an element cannot be broken down into simpler substances by a chemical change. The correct option is option A.
To know more about element, here:
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Please can I have help on question e as I’m really stuck.I promise I’ll give out brainiest
The relative atomic mass of element A : 6.075 u
Further explanationThe elements in nature have several types of isotopes
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ...
Element A
mass number of isotope 1 = 6 , percent : 92.5%
mass number of isotope 2 = 7, percent : 7.5
Relative atomic mass of element A
[tex]\tt = 92.5\%\times 6+7.5\%\times 7\\\\=5.55+0.525=6.075~u[/tex]
An unknown metal cation (alias, M) contains 26 total electrons. It forms an ionic compound
with sulfide with the formula MS. What is the symbol of the cation?
*When writing the cation, write the symbol, put in 1 space, then the charge.
Example: Fe2+ would be written Fe 2+
Answer:
sulfide is S 2- so it will be M 2+
What is tetanus? What are the symptoms and consequences of the disease? Who is at risk of developing tetanus? How do vaccines work? What is the history of the tetanus vaccine? Who should receive the tetanus vaccine? When should people receive the tetanus vaccine? Why is this schedule important? Has there been a change in tetanus incidence in the United States since the vaccine became available? What are the risks of vaccination versus non-vaccination? Do the risks outweigh the benefits? Are there areas in the world in which tetanus is prevalent? If so, does this affect the recommendations for US vaccination?
Answer:
The tetanus vaccine is a dose of the bacterium Clostridium Tetani, in inactive form or even a surface molecule that helps the body to actively form the antibody.
The tetanus vaccine has coverage for life, it is mandatory in those countries where the disease became common, such as the USA, Argentina, Chile, Uruguay among others.
Before a surgical act or a suspicion of exposure with this bacterium, the booster of the tetanus vaccine should be administered quickly.
Explanation:
Tetanus disease generates a tetanization of all the muscles of the organism, generating spasmodic contractions, which make it impossible to function and develop life when it affects the diaphragm as it makes breathing impossible.
Tetanization does not affect differently in age or sex, it only consists of contamination with the bacteria to be sufficient.
The sources of contagion are areas of mud or earth, rusty cutting or sharp elements, and poorly hygienic or abandoned areas. In order for the bacteria to be transmitted or the transmission route to be fulfilled, there must be a lesion of loss of continuity of the epithelium or mucosa.
Whas the the ionic radius of strontium
Answer: 255 pm
Explanation: Hope this helps!
Explain three ways the periodic table is organized. Include in your essay the
definition of two listed trends and the patterns observed for each of your selected
trends on the periodic table
Answer:
The periodic table is organized in non-metals metals and metalloids, in in terms of trends and patterns you may want to talk about the the density of the elements or the mass of per unit of measurement of whatever you're going to use sorry that could be much help but I hope it helps.
Neturally an atom is neutral in charge why
Answer
Explanation:
an atom is usually define as a perfect balance of electrons and protons
List the different sizes of sediment.
Answer:
Smallest to Largest:
Clay is smaller then 1/125 mm
Silt is 1/256- 1/16 mm
Sand is 1/16-2 mm
Pebble is 2-64 mm
Cobble is 64-256 mm
Boulder is greater then 256 mm
Explanation:
what is the definition of chemical formula?
Answer:
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus and minus signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than are chemical names and structural formulae.
Explanation:
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