36 颗豆豆
1. 单选题
20 秒
What is it?
animal cell
plant cell
atom
electron
2. 单选题
20 秒
which one is not a part of a plant?
stem
flower
leaaf
cartilage
3. 单选题
20 秒
which process(过程) absorbs energy?
transpiration
active energy
photosynthesis
respiration
4. 单选题
20 秒
O2 and CO2 in and out of leaves through ______?
chlorophyll
stomata
stem
xylem
5. 单选题
20 秒
The name of Ca(OH)2 is _____.
calcium hydrogen oxide
calcium dihydroxide
calcium hydroxide two
calcium hydroxide
6. 单选题
20 秒
Balance: ___N2 + ___O2 → ___N2O5
1,5,2
2,5,2
1,5,1
2,5,1
7. 单选题
20 秒
Balance: ___Al + ___O2 → ___Al2O3
4,3,2
2,3,2
4,2,3
2,4,3
8. 单选题
20 秒
A Potassium atom has _____ protons inside.
12
9
11
19
9. 单选题
20 秒
which one is most reactive?
Ca
Zn
Ag
K
10. 单选题
20 秒
Which one is dinitrogen tetroxide?
NO4
N2O
N2O5
N2O4
11. 单选题
20 秒
An atom has 8 neutrons, 6 protons and 6 electrons
It is a Oxygen atom
it is a positive charged ion
It has 14 nucleons.
it is a metal element
12. 单选题
20 秒
Oxygen ion (O2-) has __________
8 neutrons
6 electrons and 8 protons
8 nucleons and 10 electrons
8 protons and 10 electrons
13. 单选题
20 秒
plants transport water by _______.
leaf
evaporation
transpiration
stomata
14. 单选题
20 秒
plants transport water through ________
root hair cell
chloroplast
xylem
phloem
15. 单选题
20 秒
Which one is not a combustion?
Mg + O2 → MgO
HCl + NaOH → NaCl + H2O
S + O2 → SO2
C + O2 → CO2
16. 单选题
20 秒
Which one is potassium hydroxide?
P(OH)3
PoOH
KOH
Pt(OH)2
17. 单选题
20 秒
Which one is the least reactive?
Iron
Zinc
Copper
Platinum
18. 单选题
20 秒
___ C3H8 + ___O2 → ___CO2 + ___H2O
1,5,3,4
1,7,3,4
2,8,6,8
1,4,3,4
19. 单选题
20 秒
Which one is correct?
It has 29 neutrons
It is silicon element
it has 15 electrons
It is a metal element
20. 单选题
20 秒
X has 9 protons, 10 neutrons and 10 electrons
The symbol of it is F
it is a positively charged ion
it is a negatively charged ion
It has 20 nucleons
21. 单选题
20 秒
Atom is neither negative or positive, because ___
No. of proton = No. of neutron
No. of nucleon = No. of proton
No. of electron = No.of proton
No.of electron = No.of neutron
22. 单选题
20 秒
Root absorbs ______ by ______
water+CO2 ; active transport
water+mineral;active transport
water+CO2 ; photosynthesis
water+mineral; photosynthesis
23. 单选题
20 秒
The energy stored by ____ and be released by ____
transpiration; photosynthesis
photosynthesis; respiration
respiration; photosynthesis
evaporation; diffusion
24. 单选题
20 秒
Name of Na2SO4 is _______
sodium sulfur tetraoxide
sodium sulfide
sodium sulfate
sodium disulfate
25. 单选题
20 秒
Which element helps plant to build chlorophyll?
N
P
K
Mg
26. 单选题
20 秒
Which element helps plant to grow strong root?
N
P
K
Mg
27. 单选题
20 秒
___ of the plant will be stronger in desert(沙漠)?
root
stem
leaf
flower
28. 单选题
20 秒
Photosynthesis is ________
endothermic
exothermic
release energy
release H2O
29. 单选题
20 秒
We can get water from juice by _____
evaporation
chromatography
distillation
filtration
30. 单选题
20 秒
we can get sand from river water by _________
evaporation
distillation
chromatography
filtration
31. 单选题
20 秒
iodine makes w starch _____.
dark blue
dark red
lilac
yellow
32. 单选题
20 秒
CaO is a ___________
element
mixture
basic oxide
acidic oxide
33. 单选题
20 秒
The electron structure of Cl atom is
2,7
2,8,7
10,7
2,8,3
34. 单选题
30 秒
___ is not in the same group with other three
lithium
sodium
helium
sodium
35. 单选题
30 秒
NF3 has _____ protons
4
32
34
71
36. 单选题
20 秒
CO2 has ______ electrons
20
3
22
24