Solution :- Q1) Tarnishing of the penny is the chemical change where chemical re

Question

Solution :-

Q1) Tarnishing of the penny is the chemical change where chemical reaction takes place on the surface of the penny. While other changes are the physical changes. So the answer is option A.

Q2) Water is the pure substance while Air is mizture of gases , milk and soil are also the mixture

Q3) 1milliliter * 1 L /1000 millilitre = 0.001 L Therefore it is option C

Q4) 0.00820 is containing 3 significant figures because the zeros in the beginning are non significant.

Q5) 0.06574 will have -2 exponent since we need to move decimal point by two places on the right side.

Q6) 2.35*10^6 has 3 sig figures therefore the lowest number of calculation in the resulting answer will be 3

Q7) mass of liquid = total mass of cylinder - mass of empty cylinder

                                  = 120.983 g -82.350 g

                                  =38.633 g

Density = mass / volume

             = 38.633 g / 45.0 ml

            =0.859 g/ml

Q8) Calcium = Ca is the correct representation

Since sodium = Na

Potassium = K

Fluoride = F

Q9) charge = proton - electron

                    = 16-18

                    = -2

Q10) Fe2(SO4)3 have 2 Fe and 3 S and 12 oxygen so total is

2+3+12=17 atoms

Q11) number of neutron = mass number - atomic number

                                            = 234-91

                                           = 143

Q12) Calcium nitride = Ca3N2

Because calcium forms +2 cation and nitride is -3 anion

Q13) HCO3^2- is the incorrect ion because bicarbonate ion have -1 charge that is HCO3^- and not -2

Q14) name of P2O5 = Diphosphorous pentaoxide

Because it have 2 phosphorous atoms and 5 oxygen atoms therefore its prefix are di and penta and suffix is 'ide'

Explanation / Answer

Which of the following is a chemical change? a. c. ice melts I. b. d. dry ice sublimes water evaporates a penny tarnishes Which is a pure substance? a. water 2. b. air c. soil d. milk One milliliter is equal to how many liters? a. 100 3. b. 1000 C. .001 d. 0.01 4. The number of significant figures contained in the number 0.00820 is: 5. When the number 0.06574 is written in correct scientific notation, the exponent 6. If the following calculation (3.678 x 102 x 10.002)+2.35 x 10° was made, the number b. 3 c. 4 d. 5 a. (power) will be: a. C. of significant figures in the answer is: a. 2 c. An empty graduated cylinder weighs 82.350 g. When filled to 45.0 mL with an unknown liquid it weighs 120.983 g. What is the density of the unknown? a. 0.859 g/'mL b. 1.83 g/mL 7. c. 2.69 g/mL d. 1.16 g/mL Which of the following combinations of element name and symbol is correct? a. fluorine, FI c. sodium, S 8. b. potassium, P d. calcium, Ca 9. A particle having 16 protons and 18 electrons has a charge of 10. How many atoms are represented in the formula Fe(SO4)s? 11. How many neutrons exist in the atom whose symbol is 234Pa? a. +2 c· +16 d. -18 a. b. 24 c. 20 b. 234 c. 143 d. 140 a. 12. The formula for the compound calcium nitride is: c. CaN2 a. Ca2N3 b. CaSO4 d. Ca3N2 13. There is an error in the formula of one of the following ions. Identify the incorrect ion. a. NOj b. Cro c. HCO, 14. The correct name for P20s is

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.