Review Three states of matter are ( ). solid, liquid and gas The process by which a liquid changes into a solid is ( ). freezing The process by which a solid changes into a liquid is ( ). melting The amount of matter in an object is its ( ). mass The amount of space an object takes up is its ( ). volume A characteristic of matter that you can observe or measure directly is a ( ). physical property
What are physical properties of matter? shape mass density texture taste hardness size volume odor
How are physical properties observed? All matter has physical properties. Some properties can be described by using your senses. You can feel hardness and see shape or color. You can feel texture and smell odor. Other properties can be measured using tools. You can measure size with a ruler. You can measure volume with a graduated cylinder (量筒). You can measure mass with a pan balance.
Changing physical properties of the wax(蜡): size, shape, texture, mass, hardness No new substance is formed.
Shredded Crumpled Soaked Folded
A physical change is a change in which a new substance is not formed.
Experiment / Observe 实验/观察 Signs of Change Experiment / Observe 实验/观察 Record 记录 观察一片白面包和一片烤焦的面包 我看到/闻到： 观察生锈与未生锈的两颗铁钉 我看到： 用火柴点燃蜡烛 手靠近蜡烛火焰，感受温度 吹灭蜡烛 观察火柴头和蜡烛芯 我看到/感受到了： 将白醋倒入盛有小苏打的烧杯中 观察烧杯内的变化 将过氧化氢倒入盛有高锰酸钾的锥形瓶中 观察锥形瓶内的变化 color change and odor color change color change. light, heat or smoke produce while burning. gas bubbles smoke
A physical change is a change in which a new substance is not formed. A chemical change is a change that causes a new substance to form.
Physical Change Chemical Change