Answer:
the color change
ANSWER THESE 5 MULTPLE CHOICE QUESTIONS!!!
I'LL GIVE 30 POINTS AND A BRAINIEST:)
Answer: 1, magnesium & mg
2, two energy shells
Explanation:
In a chemical reaction _________ are the substances present after the reaction?
(PLEASE HELP! I NEED TO GET THIS DONE BY 11:00 PM! SOMEONE TELL ME HOW TO GIVE BRAINILIST BEACAUSE THE PERSON THAT GETS THIS I WILL GIVE BRAINALIST! BUT I DONT KNOW HOW TO SO TELL ME PLEASE! HELPPPPPPPPPPPPPPPP!)
P.S(sorry about the long yelling and again... im in middle school so I am just going to pick chemistry because I don’t know which subject this is, it just says photosynthesis)
Answer:
The substances present after the reaction are called products.
Explanation.
They are called reactants at the start of the reaction.
________ is defined as average kinetic energy.
A. temperature
B. volume
C. heat
D. pressure
Can someone answer this pleasee it’s free 15 points
I don’t know
but thank u for the points
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Did you know?
Hawaii is the Widest State in America!!!!!!!
8
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Which of the following statements is FALSE about the diagrams above?
Diagram B is a mixture of compounds.
Diagram C is a pure substance of a diatomic element.
Diagram D is a mixture of elements and compounds.
Diagrams A&C represent a pure substance of elements.
14 15
Answer:
Diagram B is a mixture of compounds
Explanation:
The false statement about any of the diagram is that diagram B is a mixture of compounds.
Diagram is not a mixture of compounds. It is a single compound in gaseous state .
A compound is a combination of elements in a definite grouping. The properties of the compound is distinct from that of the element that combines to form it. Therefore, since we just a black and yellow circle, the diagram is a compound and nothing more. The other descriptions are perfect.What is the balanced equation for KOH+CO2—>K2CO3+H2O
The balanced equation :
2KOH+CO₂⇒K₂CO₃+H₂O
Further explanationEqualization of chemical reaction equations can be done using variables. Steps in equalizing the reaction equation:
1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c etc.
2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index between reactant and product
3. Select the coefficient of the substance with the most complex chemical formula equal to 1
Reaction
KOH+CO₂⇒K₂CO₃+H₂O
give coeffiecientaKOH+bCO₂⇒K₂CO₃+cH₂O
make equationK, left=a, right=2⇒a=2
H, left=a, right=2c⇒a=2c⇒2=2c⇒c=1
O, left=a+2b, right=3+c⇒a+2b=3+c⇒2+2b=3+1⇒2b=2⇒b=1
the equation becomes :
2KOH+CO₂⇒K₂CO₃+H₂O
6. Which of the following molecules has a central atom with precisely two unshared
pairs of electrons?
methane, CH4
ammonia, NH3
hydrocyanic acid, HCN
water, H20
CLEAR ALL
Answer:
water, H20
Explanation:
From the given choices, only water has two unshared or lone pairs of electrons in its central atom.
The formula of water is:
H₂O
H is hydrogen with 1 electron
O is oxygen with 8 electrons and 6 valence electrons
To form the covalent bond, the 6 valence electrons are involved. Two out of the 6 bonds with the two oxygen.
The remaining 4 gives the two lone pairs.
Compute the number of ions in 58.5 g oh nacl
Answer: Explanation:
58.5 g of Na Cl = 1 mole 5.85 g ofNaCl = 1 X 5.85/58.5 = 0.1 mole Each molecule of NaCI contains one Na ion and one Cl ion = 2 ions Total moles of ions in 0.1 mole of NaCI = 2 x 0.1 = 0.2 molesWhat is the number of valance electrons for oxygen
Answer:
six
Explanation:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell.
Answer:
Six!
Explanation:
Valence electrons are the electrons in the outermost shell of an atom.
What is the mass in grams of 10 moles of ammonia, NH3?
A.
?
1.7 grams
B.
?
27 grams
C. ?
170 grams
D
?
0.587 grams
Answer:
C. 170 g.
Explanation:
multiply given moles by the molar mass of ammonia.