Measurement in Science

These flashcards cover key concepts related to measurements and states of matter as discussed in the lecture notes.

Millimeters

A unit of length in the metric system equal to one thousandth of a meter.

Centimeters

A unit of length in the metric system equal to one hundredth of a meter.

Meters

A unit of length in the metric system that is the base unit of length.

Meniscus

The curve of water at the surface in a graduated cylinder or other container.

Precision

The degree to which repeated measurements under unchanged conditions show the same results.

Graduated Cylinder

A laboratory instrument used to measure the volume of a liquid.

Liquid

A state of matter that has a definite volume but no definite shape.

Solid

A state of matter characterized by structural rigidity and resistance to changes of shape or volume.

Gas

A state of matter without a defined volume or shape, expanding to fill its container.

heterogeneous

substance, mixture, or system made of different, distinguishable parts or components that are not uniformly blended, often with visible boundaries and multiple phases (like solid, liquid, gas) that can usually be separated physically,

homogeneous

having a uniform composition or structure throughout, made of the same kind of parts, with substances evenly distributed so they can't be distinguished visually.

substance or non mixture

cannot be separated by physical means

mixture

made up of two separate types of matter that can be physically separated

matter

A classification of anything that has mass and takes up space

element

has only one kind of atom in the sample

compound

contains two kinds of atoms that cannot physically be separated

tomato soup

homogenous

chex mix

heterogeneous

physical change

when something changes phase or it changes but stays the same element

Chemical change

When elements combine or change their molecular compound

ion

positive or negatively charged at because electrons have been gained or lost

anion

A negativley charged ion

cation

positively charged atom

neutral

An atom with the same number of protons and electrons

Octet rule

says atoms will gain, loose or share electrons in order to have a valence electrons

valence electrons

The electrons involved in chemical bonding

periodic table is organized by

Atomic number

nonmetal+nonmetal

use prefixes

combustion

exo

if it gets cold

Endothermic

if it gets hot

Exothermic

if it absorbs heat

Endothermic

two electrons will…

repel

an electron and a proton will…

attract

how can protons and neutrons stay together in the nucleus?

Because they attract each other

what are the neutrons in the nucleus for?

Holding the nucleus together