(i) Liang - liang stoma lebih banyak di bahagian bawah daun berbanding di bahagian atas permukaan daun.
(ii) Struktur X berfungsi mangawal pembukaan dan penutupan liang stoma
Subtract to find the temperature changes
for the water and the metal.
Answer:
???what metal????????????
help me with this attachment please
Answer:
See explanation
Explanation:
Let us recall that the basic rule in writing balanced chemical reaction equations is that the number of atoms of each element on the right hand side of the reaction equation is the same of the number of atoms of the same element on the left hand side of the reaction equation.
The reaction of red hot iron and steam is written as follows;
3Fe + 4H2O → Fe3O4 + 4H2.
The decomposition reaction of ammonium dichromate is written as;
(NH4)2Cr2O7 → N2 + Cr2O3 + 4H2O
Reaction of aluminium, sodium hydroxide and water is as follows,
2Al + 2NaOH + 2H2O ----> 2NaAlO2 + 3H2
Reaction of potassium bicarbonate with sulphuric acid;
2KHCO3 + H2SO4 -------> K2SO4 + 2H2O + 2CO2
Reaction of zinc and sodium hydroxide is as follows;
Zn + 2NaOH→Na2ZnO2 + H2
Which group on the periodic table contains chemical elements that are shiny and conduct electricity?
A.
Metalloids
B.
Nonmetals
C.
Representative elements
D.
Metals
name the gas which is formed when coal is heated in the absense of air
Answer:
Coke
Explanation:
A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon.
rare earth elements plz
Answer:
Rare earth elements are lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground.
Explanation:
The rare earth elements (REE) are a set of seventeen metallic elements. These include the fifteen lanthanides on the periodic table plus scandium and yttrium. Rare earth elements are an essential part of many high-tech devices.
What type of nuclear decay is shown by the reaction below?
A. Alpha
B. Gamma
C. Beta
O D. Fission
Answer:
C. Beta
Explanation:
State the name(s) of the sub-atomic particle(s) that have/has a positive charge. Answer with the name of the particle(s) only.
A. Neurons
B. Protons
C. Electrons
Answer:
protons because they have the most positive charge
An oxygen atom has 8 protons. What number of neutrons would make an
oxygen atom most stable?
A. 10
B. 6
C. 12
D. 8
D. 8
Hope this helps! :)
______________
Answer:
D: 8 neutrons would make it most stable
Why do we need to know these organic molecules?
Are they important to living things?
Answer:
Organic molecules are important to living things because life is based on the properties of carbon.
Properties of Carbon
Carbon is an important element because it can form four covalent bonds.
Carbon skeletons can vary in length, branching, and ring structure.
The carbon skeletons contain the functional groups that are involved in biochemical
Explanation:
Hope it helps
Increasing the concentration increases the speed of reaction by... increasing the number of collisions between products increasing the amount of energy in the system increasing the number of collisions between reactants lowering the activation energy of the reaction
Answer: increasing the number of collisions between reactants
Explanation:
A reaction is possible due to collisions between the reactants to create products. If we increase the concentration of reactants then that means that we are increasing the molecules of the reactants which would give them more chances to collide and make products.
For instance, using a non-chemistry example, if there are few cars in a large city, the accidents there will be less because the cars will have such space that they wouldn't collide with each other. If the number of cars in the city is increased however, there is now less space and more chances for cars to collide.
Help please I’ll give you brainless
Answer:
Step 9
Explanation:
The reason i selected step 9, is if you take a look at the picture hes setting up a funnel,With filter paper and if you take a look at number ''9'' questions it says set up a funnel, filter paper and filter flask which is shown in the picture on top that's how i got my answer
What is a reaction rate
Answer:
Explanation:
A reaction rate is the measure of the change in concentration of the disappearance of reactants or the change in concentration of the appearance of products per unit time
Please I need an explanation on the relationship between concentration and volume of reacting substances
Answer:
when d volume of a substance is high, the concentration is gonna b low...
Jus lyk putting much water in just a cube of sugar
Explanation:
So lower volume, higher concentration
A molecule has four bonded atoms around a central atom. The central atom does not have any lone pairs of electrons. What is the geometry of the molecule?
Answer:
Tetrahedral. Tetra- signifies four, and -hedral relates to a face of a solid; “tetrahedral” literally means “having four faces. ” This shape is found when there are four bonds all on one central atom, with no lone electron pairs. In accordance with the VSEPR theory, the bond angles between the electron bonds are 109.5o ...
There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the geometry of given molecule is tetrahedral.
What is VSEPR theory?
VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.
According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element.
A molecule has four bonded atoms around a central atom. The central atom does not have any lone pairs of electrons. The geometry of such molecule is Tetrahedral. Geometry does not include lone pair on central atom.
Therefore, the geometry of given molecule is tetrahedral.
To know more about VSEPR theory, here:
https://brainly.com/question/19582124
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Which two of the following changes of state involve solids?
Select two (2) answers
A. melting
B. boiling
C. freezing
D. evaporating
Answer:
Answer is A... Melting and freezing