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WorksheetsG6-Topic 5-Unit test
Total questions: 50
Worksheet time: 50mins
Which of the following is a sign that a chemical reaction has occurred?
change in shape
melting
formation of a gas
dissolving
This kind of matter can be poured and takes the shape of its container
gas
liquid
solid
Which of the following is a sign that a physical change has occurred?
Bubbles forming
The object being broken into smaller pieces
Heat being produced
Light being produced
Burning is an example of (a) change.
Which type of change is this?
Reversible
Irreversible
Fireworks exploding in the sky undergo a physical change.
TRUE
FALSE
Rusting of iron is a _______________ change
Reversible change
Irreversible change
Which state of matter does this picture show?
Solid
Liquid
Gas
Which of the following signs show that a chemical change has taken place?
production of a gas
production of a smell
change in energy
all of these
A sign of a chemical change on a piece of iron that has an orange colour?
light
bubbles
rust
heat
Which is an example of a different substance being formed?
glass breaking
metal melting
water freezing
wood burning
Which of the following is an example of physical change?
digesting food
a nail rusting
breaking a pencil
frying an egg
Which substance is used to prove that an unknown gas is carbon dioxide?
a glowing splint
hydrogen gas
plain drinking water
lime water
Carbon dioxide is added to soft drinks like Coca-cola and Sprite. Why is this done?
To improve the flavor
To make the drink interesting
To ensure that the drink is free of bacteria
To add bubbles to the drink
What is the function of the teeth in digestion?
to dissolve food
to break down food into smaller pieces
to absorb nutrients
to absorb water
人们用发霉的豆腐制作腐乳，这个过程发生了
化学变化
物理变化
可逆变化
Stomach produces gastric juices that break down, mix, and churn food being taken to become thin liquid.
True
False
Which of the following is an example of a chemical change?
Ice melting
Boiling water
Wood burning
What is the state of matter where particles have the most energy and are far apart?
Solid
Liquid
Gas
一位同学在做小苏打和白醋混合的实验时，将第一勺小苏打加入白醋中，看到杯子中产生气泡，当他加到第四勺小苏打时杯子里不再有气泡产生，这个时候杯子里肯定没有（ ）。
白醋
小苏打
小苏打和白醋
A change which results in the production of new substances.
(a)
To put into proper order.
(a)
To change the order.
(a)
A gas that is essential for respiration and is found in the air.
(a)
A colorless gas produced by breathing out and by burning carbon-based materials.
(a)
下列不能防止铁生锈的做法是
轴承涂油
表面涂漆
放入盐水中
放入食用油里
含有淀粉的物质（比如面包）遇到碘酒会变成
蓝色
绿色
红色
烟花爆炸后消失在天际，说明物质会消失
这种说法正确
这种说法错误
“春蚕到死丝方尽，蜡炬成灰泪始干”中描述的情景不包括化学变化
正确
错误
用完菜刀后将其清洗并擦干水分再放到干燥的地方，这是为了切断铁和（ ）的接触，以防止生锈这种（ ）的发生
水，物理变化
水，化学变化
细菌，物理变化
细菌，化学变化
我们的呼吸离不开氧气，大气中的氧气主要是由（ ）制造的。
动物
植物
人类
下列变化中属于化学变化的是
虾煮熟后变红
虾从水底浮到水面
虾被折断虾须
把一根燃烧的火柴伸进刚混合有白醋和小苏打的玻璃杯中，火柴会（ ）
燃烧得更旺
没有变化
立即熄灭
Alex将收集到的二氧化碳气体通入到澄清石灰水中，发现澄清的石灰水变浑浊（生成了白色沉淀），由此可推断该变化为（ ）
物理变化
化学变化
金属生锈后，用砂纸把铁锈磨下去，金属就不会再生锈了
正确
错误
红墨水滴入净水中，水的颜色慢慢由透明变成淡红色，这个过程发生了颜色的变化，所以是化学变化
正确
错误
下列食物中，淀粉含量最高的是
猪肉
胡萝卜
土豆
番茄
导致米饭在口腔内发生化学变化的主要原因是
牙齿
唾液
舌头
Most chemical changes cannot be reversed.
True
False
What is an example of a physical change?
cutting fabric
cooking a steak
burning paper
mixing an acid and a base
The chocolate bar in this picture turns into liquid chocolate by ______________
Evaporation
Dissolving
Melting
Freezing
